Oracle Interview Questions and Answers

1. What are the components of physical database structure of Oracle database?
Oracle database is comprised of three types of files. One or more datafiles, two are more redo log files, and one or more control files.

2. What are the components of logical database structure of Oracle database?
There are tablespaces and database's schema objects.

3. What is a tablespace?
A database is divided into Logical Storage Unit called tablespaces. A tablespace is used to grouped related logical structures together.

4. What is SYSTEM tablespace and when is it created?
Every Oracle database contains a tablespace named SYSTEM, which is automatically created when the database is created. The SYSTEM tablespace always contains the data dictionary tables for the entire database.

5. Explain the relationship among database, tablespace and data file ?
Each databases logically divided into one or more tablespaces one or more data files are explicitly created for each tablespace.

6. What is schema?
A schema is collection of database objects of a user.

7. What are Schema Objects?
Schema objects are the logical structures that directly refer to the database's data. Schema objects include tables, views, sequences, synonyms, indexes, clusters, database triggers, procedures, functions packages and database links.

8. Can objects of the same schema reside in different tablespaces?
Yes.

9. Can a tablespace hold objects from different schemes?
Yes.

10. What is Oracle table?
A table is the basic unit of data storage in an Oracle database. The tables of a database hold all of the user accessible data. Table data is stored in rows and columns.

11. What is an Oracle view?
A view is a virtual table. Every view has a query attached to it. (The query is a SELECT statement that identifies the columns and rows of the table(s) the view uses.)

12. What is Partial Backup ?
A Partial Backup is any operating system backup short of a full backup, taken while the database is open or shut down.

13. What is Mirrored on-line Redo Log ?

14. A mirrored on-line redo log consists of copies of on-line redo log files physically located on separate disks, changes made to one member of the group are made to all members.

15. What is Full Backup ?
A full backup is an operating system backup of all data files, on-line redo log files and control file that constitute ORACLE database and the parameter.

16. Can a View based on another View ?
Yes.

17. Can a Tablespace hold objects from different Schemes ?
Yes.

18. Can objects of the same Schema reside in different tablespace ?
Yes.

19. What is the use of Control File ?
When an instance of an ORACLE database is started, its control file is used to identify the database and redo log files that must be opened for database operation to proceed. It is also used in database recovery.

20. Do View contain Data ?
Views do not contain or store data.

21. What are the Referential actions supported by FOREIGN KEY integrity constraint ?
UPDATE and DELETE Restrict - A referential integrity rule that disallows the update or deletion of referenced data. DELETE Cascade - When a referenced row is deleted all associated dependent rows are deleted.

22. What are the type of Synonyms?
There are two types of Synonyms Private and Public.

23. What is a Redo Log ?
The set of Redo Log files YSDATE,UID,USER or USERENV SQL functions, or the pseudo columns LEVEL or ROWNUM.

24. What is an Index Segment ?
Each Index has an Index segment that stores all of its data.

25. Explain the relationship among Database, Tablespace and Data file?
Each databases logically divided into one or more tablespaces one or more data files are explicitly created for each tablespace

26. What are the different type of Segments ?
Data Segment, Index Segment, Rollback Segment and Temporary Segment.

27. What are Clusters ?
Clusters are groups of one or more tables physically stores together to share common columns and are often used together.

28. What is an Integrity Constrains ?
An integrity constraint is a declarative way to define a business rule for a column of a table.

29. What is an Index ?
An Index is an optional structure associated with a table to have direct access to rows, which can be created to increase the performance of data retrieval. Index can be created on one or more columns of a table.

30. What is an Extent ?
An Extent is a specific number of contiguous data blocks, obtained in a single allocation, and used to store a specific type of information.

31. What is a View ?
A view is a virtual table. Every view has a Query attached to it. (The Query is a SELECT statement that identifies the columns and rows of the table(s) the view uses.)

32. What is Table ?
A table is the basic unit of data storage in an ORACLE database. The tables of a database hold all of the user accessible data. Table data is stored in rows and columns.

33. Can a view based on another view?
Yes.

34. What are the advantages of views?
- Provide an additional level of table security, by restricting access to a predetermined set of rows and columns of a table.
- Hide data complexity.
- Simplify commands for the user.
- Present the data in a different perspective from that of the base table.
- Store complex queries.

35. What is an Oracle sequence?
A sequence generates a serial list of unique numbers for numerical columns of a database's tables.

36. What is a synonym?
A synonym is an alias for a table, view, sequence or program unit.

37. What are the types of synonyms?
There are two types of synonyms private and public.

38. What is a private synonym?
Only its owner can access a private synonym.

39. What is a public synonym?
Any database user can access a public synonym.

40. What are synonyms used for?
- Mask the real name and owner of an object.
- Provide public access to an object
- Provide location transparency for tables, views or program units of a remote database.
- Simplify the SQL statements for database users.

41. What is an Oracle index?
An index is an optional structure associated with a table to have direct access to rows, which can be created to increase the performance of data retrieval. Index can be created on one or more columns of a table.

42. How are the index updates?
Indexes are automatically maintained and used by Oracle. Changes to table data are automatically incorporated into all relevant indexes.

43. What is a Tablespace?
A database is divided into Logical Storage Unit called tablespace. A tablespace is used to grouped related logical structures together

44. What is Rollback Segment ?
A Database contains one or more Rollback Segments to temporarily store "undo" information.

45. What are the Characteristics of Data Files ?
A data file can be associated with only one database. Once created a data file can't change size. One or more data files form a logical unit of database storage called a tablespace.

46. How to define Data Block size ?
A data block size is specified for each ORACLE database when the database is created. A database users and allocated free database space in ORACLE data blocks. Block size is specified in INIT.ORA file and can’t be changed latter.

47. What does a Control file Contain ?
A Control file records the physical structure of the database. It contains the following information.
Database Name
Names and locations of a database's files and redolog files.
Time stamp of database creation.

48. What is difference between UNIQUE constraint and PRIMARY KEY constraint ?

49. A column defined as UNIQUE can contain Nulls while a column defined as PRIMARY KEY can't contain Nulls.

50. What is Index Cluster ?
A Cluster with an index on the Cluster Key

51. When does a Transaction end ?
When it is committed or Rollbacked.

52. What is the effect of setting the value "ALL_ROWS" for OPTIMIZER_GOAL parameter of the ALTER SESSION command ? What are the factors that affect OPTIMIZER in choosing an Optimization approach ?
Answer The OPTIMIZER_MODE initialization parameter Statistics in the Data Dictionary the OPTIMIZER_GOAL parameter of the ALTER SESSION command hints in the statement.

53. What is the effect of setting the value "CHOOSE" for OPTIMIZER_GOAL, parameter of the ALTER SESSION Command ?
The Optimizer chooses Cost_based approach and optimizes with the goal of best throughput if statistics for atleast one of the tables accessed by the SQL statement exist in the data dictionary. Otherwise the OPTIMIZER chooses RULE_based approach.

54. How does one create a new database? (for DBA)
One can create and modify Oracle databases using the Oracle "dbca" (Database Configuration Assistant) utility. The dbca utility is located in the $ORACLE_HOME/bin directory. The Oracle Universal Installer (oui) normally starts it after installing the database server software.
One can also create databases manually using scripts. This option, however, is falling out of fashion, as it is quite involved and error prone. Look at this example for creating and Oracle 9i database:
CONNECT SYS AS SYSDBA
ALTER SYSTEM SET DB_CREATE_FILE_DEST='/u01/oradata/';
ALTER SYSTEM SET DB_CREATE_ONLINE_LOG_DEST_1='/u02/oradata/';
ALTER SYSTEM SET DB_CREATE_ONLINE_LOG_DEST_2='/u03/oradata/';
CREATE DATABASE;

55. What database block size should I use? (for DBA)
Oracle recommends that your database block size match, or be multiples of your operating system block size. One can use smaller block sizes, but the performance cost is significant. Your choice should depend on the type of application you are running. If you have many small transactions as with OLTP, use a smaller block size. With fewer but larger transactions, as with a DSS application, use a larger block size. If you are using a volume manager, consider your "operating system block size" to be 8K. This is because volume manager products use 8K blocks (and this is not configurable).

56. What are the different approaches used by Optimizer in choosing an execution plan ?
Rule-based and Cost-based.

57. What does ROLLBACK do ?
ROLLBACK retracts any of the changes resulting from the SQL statements in the transaction.

58. How does one coalesce free space ? (for DBA)
SMON coalesces free space (extents) into larger, contiguous extents every 2 hours and even then, only for a short period of time.
SMON will not coalesce free space if a tablespace's default storage parameter "pctincrease" is set to 0. With Oracle 7.3 one can manually coalesce a tablespace using the ALTER TABLESPACE ... COALESCE; command, until then use:
SQL> alter session set events 'immediate trace name coalesce level n';
Where 'n' is the tablespace number you get from SELECT TS#, NAME FROM SYS.TS$;
You can get status information about this process by selecting from the SYS.DBA_FREE_SPACE_COALESCED dictionary view.

59. How does one prevent tablespace fragmentation? (for DBA)
Always set PCTINCREASE to 0 or 100.
Bizarre values for PCTINCREASE will contribute to fragmentation. For example if you set PCTINCREASE to 1 you will see that your extents are going to have weird and wacky sizes: 100K, 100K, 101K, 102K, etc. Such extents of bizarre size are rarely re-used in their entirety. PCTINCREASE of 0 or 100 gives you nice round extent sizes that can easily be reused. E.g.. 100K, 100K, 200K, 400K, etc.

Use the same extent size for all the segments in a given tablespace. Locally Managed tablespaces (available from 8i onwards) with uniform extent sizes virtually eliminates any tablespace fragmentation. Note that the number of extents per segment does not cause any performance issue anymore, unless they run into thousands and thousands where additional I/O may be required to fetch the additional blocks where extent maps of the segment are stored.

60. Where can one find the high water mark for a table? (for DBA)
There is no single system table, which contains the high water mark (HWM) for a table. A table's HWM can be calculated using the results from the following SQL statements:
SELECT BLOCKS
FROM DBA_SEGMENTS
WHERE OWNER=UPPER(owner) AND SEGMENT_NAME = UPPER(table);
ANALYZE TABLE owner.table ESTIMATE STATISTICS;
SELECT EMPTY_BLOCKS
FROM DBA_TABLES
WHERE OWNER=UPPER(owner) AND SEGMENT_NAME = UPPER(table);
Thus, the tables' HWM = (query result 1) - (query result 2) - 1
NOTE: You can also use the DBMS_SPACE package and calculate the HWM = TOTAL_BLOCKS - UNUSED_BLOCKS - 1.

61. What is COST-based approach to optimization ?
Considering available access paths and determining the most efficient execution plan based on statistics in the data dictionary for the tables accessed by the statement and their associated clusters and indexes.

62. What does COMMIT do ?
COMMIT makes permanent the changes resulting from all SQL statements in the transaction. The changes made by the SQL statements of a transaction become visible to other user sessions transactions that start only after transaction is committed.

63. How are extents allocated to a segment? (for DBA)
Oracle8 and above rounds off extents to a multiple of 5 blocks when more than 5 blocks are requested. If one requests 16K or 2 blocks (assuming a 8K block size), Oracle doesn't round it up to 5 blocks, but it allocates 2 blocks or 16K as requested. If one asks for 8 blocks, Oracle will round it up to 10 blocks.
Space allocation also depends upon the size of contiguous free space available. If one asks for 8 blocks and Oracle finds a contiguous free space that is exactly 8 blocks, it would give it you. If it were 9 blocks, Oracle would also give it to you. Clearly Oracle doesn't always round extents to a multiple of 5 blocks.
The exception to this rule is locally managed tablespaces. If a tablespace is created with local extent management and the extent size is 64K, then Oracle allocates 64K or 8 blocks assuming 8K-block size. Oracle doesn't round it up to the multiple of 5 when a tablespace is locally managed.

64. Can one rename a database user (schema)? (for DBA)
No, this is listed as Enhancement Request 158508. Workaround:
Do a user-level export of user A
create new user B
Import system/manager fromuser=A touser=B
Drop user A

65. Define Transaction ?
A Transaction is a logical unit of work that comprises one or more SQL statements executed by a single user.

66. What is Read-Only Transaction ?
A Read-Only transaction ensures that the results of each query executed in the transaction are consistant with respect to the same point in time.

67. What is a deadlock ? Explain .
Two processes wating to update the rows of a table which are locked by the other process then deadlock arises. In a database environment this will often happen because of not issuing proper row lock commands. Poor design of front-end application may cause this situation and the performance of server will reduce drastically.
These locks will be released automatically when a commit/rollback operation performed or any one of this processes being killed externally.

68. What is a Schema ?
The set of objects owned by user account is called the schema.

69. What is a cluster Key ?
The related columns of the tables are called the cluster key. The cluster key is indexed using a cluster index and its value is stored only once for multiple tables in the cluster.

70. What is Parallel Server ?
Multiple instances accessing the same database (Only In Multi-CPU environments)

71. What are the basic element of Base configuration of an oracle Database ?
It consists of
one or more data files.
one or more control files.
two or more redo log files.
The Database contains
multiple users/schemas
one or more rollback segments
one or more tablespaces
Data dictionary tables
User objects (table,indexes,views etc.,)
The server that access the database consists of
SGA (Database buffer, Dictionary Cache Buffers, Redo log buffers, Shared SQL pool)
SMON (System MONito)
PMON (Process MONitor)
LGWR (LoG Write)
DBWR (Data Base Write)
ARCH (ARCHiver)
CKPT (Check Point)
RECO
Dispatcher
User Process with associated PGS

72. What is clusters ?
Group of tables physically stored together because they share common columns and are often used together is called Cluster.

73. What is an Index ? How it is implemented in Oracle Database ?
An index is a database structure used by the server to have direct access of a row in a table. An index is automatically created when a unique of primary key constraint clause is specified in create table comman (Ver 7.0)

74. What is a Database instance ? Explain
A database instance (Server) is a set of memory structure and background processes that access a set of database files.
The process can be shared by all users. The memory structure that are used to store most queried data from database. This helps up to improve database performance by decreasing the amount of I/O performed against data file.

75. What is the use of ANALYZE command ?
To perform one of these function on an index, table, or cluster:
- To collect statistics about object used by the optimizer and store them in the data dictionary.
- To delete statistics about the object used by object from the data dictionary.
- To validate the structure of the object.
- To identify migrated and chained rows of the table or cluster.

76. What is default tablespace ?
The Tablespace to contain schema objects created without specifying a tablespace name.

77. What are the system resources that can be controlled through Profile ?
The number of concurrent sessions the user can establish the CPU processing time available to the user's session the CPU processing time available to a single call to ORACLE made by a SQL statement the amount of logical I/O available to the user's session the amout of logical I/O available to a single call to ORACLE made by a SQL statement the allowed amount of idle time for the user's session the allowed amount of connect time for the user's session.

78. What is Tablespace Quota ?
The collective amount of disk space available to the objects in a schema on a particular tablespace.

79. What are the different Levels of Auditing ?
Statement Auditing, Privilege Auditing and Object Auditing.

80. What is Statement Auditing ?
Statement auditing is the auditing of the powerful system privileges without regard to specifically named objects.

81. What are the database administrators utilities available ?
SQL * DBA - This allows DBA to monitor and control an ORACLE database. SQL * Loader - It loads data from standard operating system files (Flat files) into ORACLE database tables. Export (EXP) and Import (imp) utilities allow you to move existing data in ORACLE format to and from ORACLE database.

82. How can you enable automatic archiving ?
Shut the database
Backup the database
Modify/Include LOG_ARCHIVE_START_TRUE in init.ora file.
Start up the database.

83. What are roles? How can we implement roles ?
Roles are the easiest way to grant and manage common privileges needed by different groups of database users. Creating roles and assigning provides to roles. Assign each role to group of users. This will simplify the job of assigning privileges to individual users.

84. What are Roles ?
Roles are named groups of related privileges that are granted to users or other roles.

85. What are the use of Roles ?
REDUCED GRANTING OF PRIVILEGES - Rather than explicitly granting the same set of privileges to many users a database administrator can grant the privileges for a group of related users granted to a role and then grant only the role to each member of the group.
DYNAMIC PRIVILEGE MANAGEMENT - When the privileges of a group must change, only the privileges of the role need to be modified. The security domains of all users granted the group's role automatically reflect the changes made to the role.
SELECTIVE AVAILABILITY OF PRIVILEGES - The roles granted to a user can be selectively enable (available for use) or disabled (not available for use). This allows specific control of a user's privileges in any given situation.
APPLICATION AWARENESS - A database application can be designed to automatically enable and disable selective roles when a user attempts to use the application.

86. What is Privilege Auditing ?
Privilege auditing is the auditing of the use of powerful system privileges without regard to specifically named objects.

87. What is Object Auditing ?
Object auditing is the auditing of accesses to specific schema objects without regard to user.

88. What is Auditing ?
Monitoring of user access to aid in the investigation of database use.

89. How does one see the uptime for a database? (for DBA )
Look at the following SQL query:
SELECT to_char (startup_time,'DD-MON-YYYY HH24: MI: SS') "DB Startup Time"
FROM sys.v_$instance;
Marco Bergman provided the following alternative solution:
SELECT to_char (logon_time,'Dy dd Mon HH24: MI: SS') "DB Startup Time"
FROM sys.v_$session
WHERE Sid=1 /* this is pmon */
/
Users still running on Oracle 7 can try one of the following queries:
Column STARTED format a18 head 'STARTUP TIME'
Select C.INSTANCE,
to_date (JUL.VALUE, 'J')
|| to_char (floor (SEC.VALUE/3600), '09')
|| ':'
-- || Substr (to_char (mod (SEC.VALUE/60, 60), '09'), 2, 2)
|| Substr (to_char (floor (mod (SEC.VALUE/60, 60)), '09'), 2, 2)
|| '.'
|| Substr (to_char (mod (SEC.VALUE, 60), '09'), 2, 2) STARTED
from SYS.V_$INSTANCE JUL,
SYS.V_$INSTANCE SEC,
SYS.V_$THREAD C
Where JUL.KEY like '%JULIAN%'
and SEC.KEY like '%SECOND%';
Select to_date (JUL.VALUE, 'J')
|| to_char (to_date (SEC.VALUE, 'SSSSS'), ' HH24:MI:SS') STARTED
from SYS.V_$INSTANCE JUL,
SYS.V_$INSTANCE SEC
where JUL.KEY like '%JULIAN%'
and SEC.KEY like '%SECOND%';
select to_char (to_date (JUL.VALUE, 'J') + (SEC.VALUE/86400), -Return a DATE
'DD-MON-YY HH24:MI:SS') STARTED
from V$INSTANCE JUL,
V$INSTANCE SEC
where JUL.KEY like '%JULIAN%'
and SEC.KEY like '%SECOND%';

90. Where are my TEMPFILES, I don't see them in V$DATAFILE or DBA_DATA_FILE? (for DBA )
Tempfiles, unlike normal datafiles, are not listed in v$datafile or dba_data_files. Instead query v$tempfile or dba_temp_files:
SELECT * FROM v$tempfile;
SELECT * FROM dba_temp_files;

91. How do I find used/free space in a TEMPORARY tablespace? (for DBA )
Unlike normal tablespaces, true temporary tablespace information is not listed in DBA_FREE_SPACE. Instead use the V$TEMP_SPACE_HEADER view:
SELECT tablespace_name, SUM (bytes used), SUM (bytes free)
FROM V$temp_space_header
GROUP BY tablespace_name;

92. What is a profile ?
Each database user is assigned a Profile that specifies limitations on various system resources available to the user.

93. How will you enforce security using stored procedures?
Don't grant user access directly to tables within the application. Instead grant the ability to access the procedures that access the tables. When procedure executed it will execute the privilege of procedures owner. Users cannot access tables except via the procedure.

94. How can one see who is using a temporary segment? (for DBA )
For every user using temporary space, there is an entry in SYS.V$_LOCK with type 'TS'.
All temporary segments are named 'ffff.bbbb' where 'ffff' is the file it is in and 'bbbb' is first block of the segment. If your temporary tablespace is set to TEMPORARY, all sorts are done in one large temporary segment. For usage stats, see SYS.V_$SORT_SEGMENT
From Oracle 8.0, one can just query SYS.v$sort_usage. Look at these examples:
select s.username, u."USER", u.tablespace, u.contents, u.extents, u.blocks
from sys.v_$session s, sys.v_$sort_usage u
where s.addr = u.session_addr
/
select s.osuser, s.process, s.username, s.serial#,
Sum (u.blocks)*vp.value/1024 sort_size
from sys.v_$session s, sys.v_$sort_usage u, sys.v_$parameter VP
where s.saddr = u.session_addr
and vp.name = 'db_block_size'
and s.osuser like '&1'
group by s.osuser, s.process, s.username, s.serial#, vp.value
/

95. How does one get the view definition of fixed views/tables?
Query v$fixed_view_definition. Example: SELECT * FROM v$fixed_view_definition WHERE view_name='V$SESSION';

96. What are the dictionary tables used to monitor a database spaces ?
DBA_FREE_SPACE
DBA_SEGMENTS
DBA_DATA_FILES.

97. How can we specify the Archived log file name format and destination?
By setting the following values in init.ora file. LOG_ARCHIVE_FORMAT = arch %S/s/T/tarc (%S - Log sequence number and is zero left paded, %s - Log sequence number not padded. %T - Thread number lef-zero-paded and %t - Thread number not padded). The file name created is arch 0001 are if %S is used. LOG_ARCHIVE_DEST = path.

98. What is user Account in Oracle database?
An user account is not a physical structure in Database but it is having important relationship to the objects in the database and will be having certain privileges.

99. When will the data in the snapshot log be used?
We must be able to create a after row trigger on table (i.e., it should be not be already available) After giving table privileges. We cannot specify snapshot log name because oracle uses the name of the master table in the name of the database objects that support its snapshot log. The master table name should be less than or equal to 23 characters. (The table name created will be MLOGS_tablename, and trigger name will be TLOGS name).

100. What dynamic data replication?
Updating or Inserting records in remote database through database triggers. It may fail if remote database is having any problem.

101. What is Two-Phase Commit ?
Two-phase commit is mechanism that guarantees a distributed transaction either commits on all involved nodes or rolls back on all involved nodes to maintain data consistency across the global distributed database. It has two phase, a Prepare Phase and a Commit Phase.

102. How can you Enforce Referential Integrity in snapshots ?
Time the references to occur when master tables are not in use. Peform the reference the manually immdiately locking the master tables. We can join tables in snopshots by creating a complex snapshots that will based on the master tables.

103. What is a SQL * NET?
SQL *NET is ORACLE's mechanism for interfacing with the communication protocols used by the networks that facilitate distributed processing and distributed databases. It is used in Clint-Server and Server-Server communications.

104. What is a SNAPSHOT ?
Snapshots are read-only copies of a master table located on a remote node which is periodically refreshed to reflect changes made to the master table.

105. What is the mechanism provided by ORACLE for table replication ?
Snapshots and SNAPSHOT LOGs

106. What is snapshots?
Snapshot is an object used to dynamically replicate data between distribute database at specified time intervals. In ver 7.0 they are read only.

107. What are the various type of snapshots?
Simple and Complex.

108. Describe two phases of Two-phase commit ?
Prepare phase - The global coordinator (initiating node) ask a participants to prepare (to promise to commit or rollback the transaction, even if there is a failure) Commit - Phase - If all participants respond to the coordinator that they are prepared, the coordinator asks all nodes to commit the transaction, if all participants cannot prepare, the coordinator asks all nodes to roll back the transaction.

109. What is snapshot log ?
It is a table that maintains a record of modifications to the master table in a snapshot. It is stored in the same database as master table and is only available for simple snapshots. It should be created before creating snapshots.

110. What are the benefits of distributed options in databases?
Database on other servers can be updated and those transactions can be grouped together with others in a logical unit.
Database uses a two phase commit.

111. What are the options available to refresh snapshots ?
COMPLETE - Tables are completely regenerated using the snapshots query and the master tables every time the snapshot referenced.
FAST - If simple snapshot used then a snapshot log can be used to send the changes to the snapshot tables.
FORCE - Default value. If possible it performs a FAST refresh; Otherwise it will perform a complete refresh.

112. What is a SNAPSHOT LOG ?
A snapshot log is a table in the master database that is associated with the master table. ORACLE uses a snapshot log to track the rows that have been updated in the master table. Snapshot logs are used in updating the snapshots based on the master table.

113. What is Distributed database ?
A distributed database is a network of databases managed by multiple database servers that appears to a user as single logical database. The data of all databases in the distributed database can be simultaneously accessed and modified.

114. How can we reduce the network traffic?
- Replication of data in distributed environment.
- Using snapshots to replicate data.
- Using remote procedure calls.

115. Differentiate simple and complex, snapshots ?
- A simple snapshot is based on a query that does not contains GROUP BY clauses, CONNECT BY clauses, JOINs, sub-query or snashot of operations.
- A complex snapshots contain atleast any one of the above.

116. What are the Built-ins used for sending Parameters to forms?
You can pass parameter values to a form when an application executes the call_form, New_form, Open_form or Run_product.

117. Can you have more than one content canvas view attached with a window?
Yes. Each window you create must have atleast one content canvas view assigned to it. You can also create a window that has manipulated content canvas view. At run time only one of the content canvas views assign to a window is displayed at a time.

118. Is the After report trigger fired if the report execution fails?
Yes.

119. Does a Before form trigger fire when the parameter form is suppressed?
Yes.

120. What is SGA?
The System Global Area in an Oracle database is the area in memory to facilitate the transfer of information between users. It holds the most recently requested structural information between users. It holds the most recently requested structural information about the database. The structure is database buffers, dictionary cache, redo log buffer and shared pool area.

121. What is a shared pool?
The data dictionary cache is stored in an area in SGA called the shared pool. This will allow sharing of parsed SQL statements among concurrent users.

122. What is mean by Program Global Area (PGA)?
It is area in memory that is used by a single Oracle user process.

123. What is a data segment?
Data segment are the physical areas within a database block in which the data associated with tables and clusters are stored.

124. What are the factors causing the reparsing of SQL statements in SGA?
Due to insufficient shared pool size.
Monitor the ratio of the reloads takes place while executing SQL statements. If the ratio is greater than 1 then increase the SHARED_POOL_SIZE.

125. What are clusters?
Clusters are groups of one or more tables physically stores together to share common columns and are often used together.

126. What is cluster key?
The related columns of the tables in a cluster are called the cluster key.

127. Do a view contain data?
Views do not contain or store data.

128. What is user Account in Oracle database?
A user account is not a physical structure in database but it is having important relationship to the objects in the database and will be having certain privileges.

129. How will you enforce security using stored procedures?
Don't grant user access directly to tables within the application. Instead grant the ability to access the procedures that access the tables. When procedure executed it will execute the privilege of procedures owner. Users cannot access tables except via the procedure.

130. What are the dictionary tables used to monitor a database space?
DBA_FREE_SPACE
DBA_SEGMENTS
DBA_DATA_FILES.

131. Can a property clause itself be based on a property clause?
Yes

132. If a parameter is used in a query without being previously defined, what diff. exist between. report 2.0 and 2.5 when the query is applied?
While both reports 2.0 and 2.5 create the parameter, report 2.5 gives a message that a bind parameter has been created.

133. What are the sql clauses supported in the link property sheet?
Where start with having.

134. What is trigger associated with the timer?
When-timer-expired.

135. What are the trigger associated with image items?
When-image-activated fires when the operators double clicks on an image itemwhen-image-pressed fires when an operator clicks or double clicks on an image item

136. What are the different windows events activated at runtimes?
When_window_activated
When_window_closed
When_window_deactivated
When_window_resized
Within this triggers, you can examine the built in system variable system. event_window to determine the name of the window for which the trigger fired.

137. When do you use data parameter type?
When the value of a data parameter being passed to a called product is always the name of the record group defined in the current form. Data parameters are used to pass data to products invoked with the run_product built-in subprogram.

138. What is difference between open_form and call_form?
when one form invokes another form by executing open_form the first form remains displayed, and operators can navigate between the forms as desired. when one form invokes another form by executing call_form, the called form is modal with respect to the calling form. That is, any windows that belong to the calling form are disabled, and operators cannot navigate to them until they first exit the called form.

139. What is new_form built-in?
When one form invokes another form by executing new_form oracle form exits the first form and releases its memory before loading the new form calling new form completely replace the first with the second. If there are changes pending in the first form, the operator will be prompted to save them before the new form is loaded.

140. What is the "LOV of Validation" Property of an item? What is the use of it?
When LOV for Validation is set to True, Oracle Forms compares the current value of the text item to the values in the first column displayed in the LOV. Whenever the validation event occurs. If the value in the text item matches one of the values in the first column of the LOV, validation succeeds, the LOV is not displayed, and processing continues normally. If the value in the text item does not match one of the values in the first column of the LOV, Oracle Forms displays the LOV and uses the text item value as the search criteria to automatically reduce the list.

141. What is the diff. when Flex mode is mode on and when it is off?
When flex mode is on, reports automatically resizes the parent when the child is resized.

142. What is the diff. when confine mode is on and when it is off?
When confine mode is on, an object cannot be moved outside its parent in the layout.

143. What are visual attributes?
Visual attributes are the font, color, pattern proprieties that you set for form and menu objects that appear in your application interface.

144. Which of the two views should objects according to possession?
view by structure.

145. What are the two types of views available in the object navigator(specific to report 2.5)?
View by structure and view by type .

146. What are the vbx controls?
Vbx control provide a simple method of building and enhancing user interfaces. The controls can use to obtain user inputs and display program outputs.vbx control where originally develop as extensions for the ms visual basic environments and include such items as sliders, rides and knobs.

147. What is the use of transactional triggers?
Using transactional triggers we can control or modify the default functionality of the oracle forms.

148. How do you create a new session while open a new form?
Using open_form built-in setting the session option Ex. Open_form('Stocks ',active, session). when invoke the multiple forms with open form and call_form in the same application, state whether the following are true/False

149. What are the ways to monitor the performance of the report?
Use reports profile executable statement. Use SQL trace facility.

150. If two groups are not linked in the data model editor, What is the hierarchy between them?
Two group that is above are the left most rank higher than the group that is to right or below it.

151. An open form can not be execute the call_form procedure if you chain of called forms has been initiated by another open form?
True

152. Explain about horizontal, Vertical tool bar canvas views?
Tool bar canvas views are used to create tool bars for individual windows. Horizontal tool bars are display at the top of a window, just under its menu bar. Vertical Tool bars are displayed along the left side of a window

153. What is the purpose of the product order option in the column property sheet?
To specify the order of individual group evaluation in a cross products.

154. What is the use of image_zoom built-in?
To manipulate images in image items.

155. How do you reference a parameter indirectly?
To indirectly reference a parameter use the NAME IN, COPY 'built-ins to indirectly set and reference the parameters value' Example name_in ('capital parameter my param'), Copy ('SURESH','Parameter my_param')

156. What is a timer?
Timer is an "internal time clock" that you can programmatically create to perform an action each time the times.

157. What are the two phases of block coordination?
There are two phases of block coordination: the clear phase and the population phase. During, the clear phase, Oracle Forms navigates internally to the detail block and flushes the obsolete detail records. During the population phase, Oracle Forms issues a SELECT statement to repopulate the detail block with detail records associated with the new master record. These operations are accomplished through the execution of triggers.

158. What are Most Common types of Complex master-detail relationships?
There are three most common types of complex master-detail relationships:
master with dependent details
master with independent details
detail with two masters

159. What is a text list?
The text list style list item appears as a rectangular box which displays the fixed number of values. When the text list contains values that can not be displayed, a vertical scroll bar appears, allowing the operator to view and select undisplayed values.

160. What is term?
The term is terminal definition file that describes the terminal form which you are using r20run.

161. What is use of term?
The term file which key is correspond to which oracle report functions.

162. What is pop list?
The pop list style list item appears initially as a single field (similar to a text item field). When the operator selects the list icon, a list of available choices appears.

163. What is the maximum no of chars the parameter can store?
The maximum no of chars the parameter can store is only valid for char parameters, which can be upto 64K. No parameters default to 23Bytes and Date parameter default to 7Bytes.

164. What are the default extensions of the files created by library module?
The default file extensions indicate the library module type and storage format .pll - pl/sql library module binary

165. What are the Coordination Properties in a Master-Detail relationship?
The coordination properties are
Deferred
Auto-Query
These Properties determine when the population phase of block
coordination should occur.

166. How do you display console on a window ?
The console includes the status line and message line, and is displayed at the bottom of the window to which it is assigned.To specify that the console should be displayed, set the console window form property to the name of any window in the form. To include the console, set console window to Null.

167. What are the different Parameter types?
Text ParametersData Parameters

168. State any three mouse events system variables?
System.mouse_button_pressedSystem.mouse_button_shift

169. What are the types of calculated columns available?
Summary, Formula, Placeholder column.

170. Explain about stacked canvas views?
Stacked canvas view is displayed in a window on top of, or "stacked" on the content canvas view assigned to that same window. Stacked canvas views obscure some part of the underlying content canvas view, and or often shown and hidden programmatically.

171. How does one do off-line database backups? (for DBA )
Shut down the database from sqlplus or server manager. Backup all files to secondary storage (eg. tapes). Ensure that you backup all data files, all control files and all log files. When completed, restart your database.
Do the following queries to get a list of all files that needs to be backed up:
select name from sys.v_$datafile;
select member from sys.v_$logfile;
select name from sys.v_$controlfile;
Sometimes Oracle takes forever to shutdown with the "immediate" option. As workaround to this problem, shutdown using these commands:
alter system checkpoint;
shutdown abort
startup restrict
shutdown immediate
Note that if you database is in ARCHIVELOG mode, one can still use archived log files to roll forward from an off-line backup. If you cannot take your database down for a cold (off-line) backup at a convenient time, switch your database into ARCHIVELOG mode and perform hot (on-line) backups.

172. What is the difference between SHOW_EDITOR and EDIT_TEXTITEM?
Show editor is the generic built-in which accepts any editor name and takes some input string and returns modified output string. Whereas the edit_textitem built-in needs the input focus to be in the text item before the built-in is executed.

173. What are the built-ins that are used to Attach an LOV programmatically to an item?
set_item_property
get_item_property
(by setting the LOV_NAME property)

174. How does one do on-line database backups? (for DBA )
Each tablespace that needs to be backed-up must be switched into backup mode before copying the files out to secondary storage (tapes). Look at this simple example.
ALTER TABLESPACE xyz BEGIN BACKUP;
! cp xyfFile1 /backupDir/
ALTER TABLESPACE xyz END BACKUP;
It is better to backup tablespace for tablespace than to put all tablespaces in backup mode. Backing them up separately incurs less overhead. When done, remember to backup your control files. Look at this example:
ALTER SYSTEM SWITCH LOGFILE; -- Force log switch to update control file headers
ALTER DATABASE BACKUP CONTROLFILE TO '/backupDir/control.dbf';
NOTE: Do not run on-line backups during peak processing periods. Oracle will write complete database blocks instead of the normal deltas to redo log files while in backup mode. This will lead to excessive database archiving and even database freezes.

175. How does one backup a database using RMAN? (for DBA )
The biggest advantage of RMAN is that it only backup used space in the database. Rman doesn't put tablespaces in backup mode, saving on redo generation overhead. RMAN will re-read database blocks until it gets a consistent image of it. Look at this simple backup example.
rman target sys/*** nocatalog
run {
allocate channel t1 type disk;
backup
format '/app/oracle/db_backup/%d_t%t_s%s_p%p'
( database );
release channel t1;
}
Example RMAN restore:
rman target sys/*** nocatalog
run {
allocate channel t1 type disk;
# set until time 'Aug 07 2000 :51';
restore tablespace users;
recover tablespace users;
release channel t1;
}
The examples above are extremely simplistic and only useful for illustrating basic concepts. By default Oracle uses the database controlfiles to store information about backups. Normally one would rather setup a RMAN catalog database to store RMAN metadata in. Read the Oracle Backup and Recovery Guide before implementing any RMAN backups.
Note: RMAN cannot write image copies directly to tape. One needs to use a third-party media manager that integrates with RMAN to backup directly to tape. Alternatively one can backup to disk and then manually copy the backups to tape.

176. What are the different file extensions that are created by oracle reports?
Rep file and Rdf file.

177. What is strip sources generate options?
Removes the source code from the library file and generates a library files that contains only pcode. The resulting file can be used for final deployment, but can not be subsequently edited in the designer.ex. f45gen module=old_lib.pll userid=scott/tiger strip_source YES output_file

178. How does one put a database into ARCHIVELOG mode? (for DBA )
The main reason for running in archivelog mode is that one can provide 24-hour availability and guarantee complete data recoverability. It is also necessary to enable ARCHIVELOG mode before one can start to use on-line database backups. To enable ARCHIVELOG mode, simply change your database startup command script, and bounce the database:
SQLPLUS> connect sys as sysdba
SQLPLUS> startup mount exclusive;
SQLPLUS> alter database archivelog;
SQLPLUS> archive log start;
SQLPLUS> alter database open;
NOTE1: Remember to take a baseline database backup right after enabling archivelog mode. Without it one would not be able to recover. Also, implement an archivelog backup to prevent the archive log directory from filling-up.
NOTE2: ARCHIVELOG mode was introduced with Oracle V6, and is essential for database point-in-time recovery. Archiving can be used in combination with on-line and off-line database backups.
NOTE3: You may want to set the following INIT.ORA parameters when enabling ARCHIVELOG mode: log_archive_start=TRUE, log_archive_dest=... and log_archive_format=...
NOTE4: You can change the archive log destination of a database on-line with the ARCHIVE LOG START TO 'directory'; statement. This statement is often used to switch archiving between a set of directories.
NOTE5: When running Oracle Real Application Server (RAC), you need to shut down all nodes before changing the database to ARCHIVELOG mode.

179. What is the basic data structure that is required for creating an LOV?
Record Group.

180. How does one backup archived log files? (for DBA )
One can backup archived log files using RMAN or any operating system backup utility. Remember to delete files after backing them up to prevent the archive log directory from filling up. If the archive log directory becomes full, your database will hang! Look at this simple RMAN backup script:
RMAN> run {
2> allocate channel dev1 type disk;
3> backup
4> format '/app/oracle/arch_backup/log_t%t_s%s_p%p'
5> (archivelog all delete input);
6> release channel dev1;
7> }

181. Does Oracle write to data files in begin/hot backup mode? (for DBA )
Oracle will stop updating file headers, but will continue to write data to the database files even if a tablespace is in backup mode.
In backup mode, Oracle will write out complete changed blocks to the redo log files. Normally only deltas (changes) are logged to the redo logs. This is done to enable reconstruction of a block if only half of it was backed up (split blocks). Because of this, one should notice increased log activity and archiving during on-line backups.

182. What is the Maximum allowed length of Record group Column?
Record group column names cannot exceed 30 characters.

183. Which parameter can be used to set read level consistency across multiple queries?
Read only

184. What are the different types of Record Groups?
Query Record Groups
NonQuery Record Groups
State Record Groups

185. From which designation is it preferred to send the output to the printed?
Previewer

186. What are difference between post database commit and post-form commit?
Post-form commit fires once during the post and commit transactions process, after the database commit occurs. The post-form-commit trigger fires after inserts, updates and deletes have been posted to the database but before the transactions have been finalized in the issuing the command. The post-database-commit trigger fires after oracle forms issues the commit to finalized transactions.

187. What are the different display styles of list items?
Pop_listText_listCombo box

188. Which of the above methods is the faster method?
performing the calculation in the query is faster.

189. With which function of summary item is the compute at options required?
percentage of total functions.

190. What are parameters?
Parameters provide a simple mechanism for defining and setting the valuesof inputs that are required by a form at startup. Form parameters are variables of type char,number,date that you define at design time.

191. What are the three types of user exits available ?
Oracle Precompiler exits, Oracle call interface, NonOracle user exits.

192. How many windows in a form can have console?
Only one window in a form can display the console, and you cannot change the console assignment at runtime.

193. What is an administrative (privileged) user? (for DBA )
Oracle DBAs and operators typically use administrative accounts to manage the database and database instance. An administrative account is a user that is granted SYSOPER or SYSDBA privileges. SYSDBA and SYSOPER allow access to a database instance even if it is not running. Control of these privileges is managed outside of the database via password files and special operating system groups. This password file is created with the orapwd utility.

194. What are the two repeating frame always associated with matrix object?
One down repeating frame below one across repeating frame.

195. What are the master-detail triggers?
On-Check_delete_masterOn_clear_detailsOn_populate_details

196. How does one connect to an administrative user? (for DBA )
If an administrative user belongs to the "dba" group on Unix, or the "ORA_DBA" (ORA_sid_DBA) group on NT, he/she can connect like this:
connect / as sysdba
No password is required. This is equivalent to the desupported "connect internal" method.
A password is required for "non-secure" administrative access. These passwords are stored in password files. Remote connections via Net8 are classified as non-secure. Look at this example:
connect sys/password as sysdba

197. How does one create a password file? (for DBA )
The Oracle Password File ($ORACLE_HOME/dbs/orapw or orapwSID) stores passwords for users with administrative privileges. One needs to create a password files before remote administrators (like OEM) will be allowed to connect.
Follow this procedure to create a new password file:
. Log in as the Oracle software owner
. Runcommand: orapwd file=$ORACLE_HOME/dbs/orapw$ORACLE_SID password=mypasswd
. Shutdown the database (SQLPLUS> SHUTDOWN IMMEDIATE)
. Edit the INIT.ORA file and ensure REMOTE_LOGIN_PASSWORDFILE=exclusive is set.
. Startup the database (SQLPLUS> STARTUP)
NOTE: The orapwd utility presents a security risk in that it receives a password from the command line. This password is visible in the process table of many systems. Administrators needs to be aware of this!

198. Is it possible to modify an external query in a report which contains it?
No.

199. Does a grouping done for objects in the layout editor affect the grouping done in the data model editor?
No.

200. How does one add users to a password file? (for DBA )
One can select from the SYS.V_$PWFILE_USERS view to see which users are listed in the password file. New users can be added to the password file by granting them SYSDBA or SYSOPER privileges, or by using the orapwd utility. GRANT SYSDBA TO scott;

201. If a break order is set on a column would it affect columns which are under the column?
No

202. Why are OPS$ accounts a security risk in a client/server environment? (for DBA)
If you allow people to log in with OPS$ accounts from Windows Workstations, you cannot be sure who they really are. With terminals, you can rely on operating system passwords, with Windows, you cannot.
If you set REMOTE_OS_AUTHENT=TRUE in your init.ora file, Oracle assumes that the remote OS has authenticated the user. If REMOTE_OS_AUTHENT is set to FALSE (recommended), remote users will be unable to connect without a password. IDENTIFIED EXTERNALLY will only be in effect from the local host. Also, if you are using "OPS$" as your prefix, you will be able to log on locally with or without a password, regardless of whether you have identified your ID with a password or defined it to be IDENTIFIED EXTERNALLY.

203. Do user parameters appear in the data modal editor in 2.5?
No

204. Can you pass data parameters to forms?
No

205. Is it possible to link two groups inside a cross products after the cross products group has been created?
no

206. What are the different modals of windows?
Modalless windows
Modal windows

207. What are modal windows?
Modal windows are usually used as dialogs, and have restricted functionality compared to modelless windows. On some platforms for example operators cannot resize, scroll or iconify a modal window.

208. What are the different default triggers created when Master Deletes Property is set to Non-isolated?
Master Deletes Property Resulting Triggers
----------------------------------------------------
Non-Isolated(the default) On-Check-Delete-Master
On-Clear-Details
On-Populate-Details

209. What are the different default triggers created when Master Deletes Property is set to isolated?
Master Deletes Property Resulting Triggers
---------------------------------------------------
Isolated On-Clear-Details
On-Populate-Details

210. What are the different default triggers created when Master Deletes Property is set to Cascade?
Master Deletes Property Resulting Triggers
---------------------------------------------------
Cascading On-Clear-Details
On-Populate-Details
Pre-delete

211. What is the diff. bet. setting up of parameters in reports 2.0 reports2.5?
LOVs can be attached to parameters in the reports 2.5 parameter form.

212. What are the difference between lov & list item?
Lov is a property where as list item is an item. A list item can have only one column, lov can have one or more columns.

213. What is the advantage of the library?
Libraries provide a convenient means of storing client-side program units and sharing them among multiple applications. Once you create a library, you can attach it to any other form, menu, or library modules. When you can call library program units from triggers menu items commands and user named routine, you write in the modules to which you have attach the library. When a library attaches another library, program units in the first library can reference program units in the attached library. Library support dynamic loading-that is library program units are loaded into an application only when needed. This can significantly reduce the run-time memory requirements of applications.

214. What is lexical reference? How can it be created?
Lexical reference is place_holder for text that can be embedded in a sql statements. A lexical reference can be created using & before the column or parameter name.

215. What is system.coordination_operation?
It represents the coordination causing event that occur on the master block in master-detail relation.

216. What is synchronize?
It is a terminal screen with the internal state of the form. It updates the screen display to reflect the information that oracle forms has in its internal representation of the screen.

217. What use of command line parameter cmd file?
It is a command line argument that allows you to specify a file that contain a set of arguments for r20run.

218. What is a Text_io Package?
It allows you to read and write information to a file in the file system.

219. What is forms_DDL?
Issues dynamic Sql statements at run time, including server side pl/SQl and DDL

220. How is link tool operation different bet. reports 2 & 2.5?
In Reports 2.0 the link tool has to be selected and then two fields to be linked are selected and the link is automatically created. In 2.5 the first field is selected and the link tool is then used to link the first field to the second field.

221. What are the different styles of activation of ole Objects?
In place activationExternal activation

222. How do you reference a Parameter?
In Pl/Sql, You can reference and set the values of form parameters using bind variables syntax. Ex. PARAMETER name = '' or :block.item = PARAMETER Parameter name

223. What is the difference between object embedding & linking in Oracle forms?
In Oracle forms, Embedded objects become part of the form module, and linked objects are references from a form module to a linked source file.

224. Name of the functions used to get/set canvas properties?
Get_view_property, Set_view_property

225. What are the built-ins that are used for setting the LOV properties at runtime?
get_lov_property
set_lov_property

226. What are the built-ins used for processing rows?
Get_group_row_count(function)
Get_group_selection_count(function)
Get_group_selection(function)
Reset_group_selection(procedure)
Set_group_selection(procedure)
Unset_group_selection(procedure)

227. What are built-ins used for Processing rows?
GET_GROUP_ROW_COUNT(function)
GET_GROUP_SELECTION_COUNT(function)
GET_GROUP_SELECTION(function)
RESET_GROUP_SELECTION(procedure)
SET_GROUP_SELECTION(procedure)
UNSET_GROUP_SELECTION(procedure)

228. What are the built-in used for getting cell values?
Get_group_char_cell(function)
Get_groupcell(function)
Get_group_number_cell(function)

229. What are the built-ins used for Getting cell values?
GET_GROUP_CHAR_CELL (function)
GET_GROUPCELL(function)
GET_GROUP_NUMBET_CELL(function)

230. Atleast how many set of data must a data model have before a data model can be base on it?
Four

231. To execute row from being displayed that still use column in the row which property can be used?
Format trigger.

232. What are different types of modules available in oracle form?
Form module - a collection of objects and code routines Menu modules - a collection of menus and menu item commands that together make up an application menu library module - a collection of user named procedures, functions and packages that can be called from other modules in the application

233. What is the remove on exit property?
For a modelless window, it determines whether oracle forms hides the window automatically when the operators navigates to an item in the another window.

234. What is WHEN-Database-record trigger?
Fires when oracle forms first marks a record as an insert or an update. The trigger fires as soon as oracle forms determines through validation that the record should be processed by the next post or commit as an insert or update. c generally occurs only when the operators modifies the first item in the record, and after the operator attempts to navigate out of the item.

235. What is a difference between pre-select and pre-query?
Fires during the execute query and count query processing after oracle forms constructs the select statement to be issued, but before the statement is actually issued. The pre-query trigger fires just before oracle forms issues the select statement to the database after the operator as define the example records by entering the query criteria in enter query mode.Pre-query trigger fires before pre-select trigger.

236. What are built-ins associated with timers?
find_timercreate_timerdelete_timer

237. What are the built-ins used for finding object ID functions?
Find_group(function)
Find_column(function)

238. What are the built-ins used for finding Object ID function?
FIND_GROUP(function)
FIND_COLUMN(function)

239. Any attempt to navigate programmatically to disabled form in a call_form stack is allowed?
False

240. Use the Add_group_row procedure to add a row to a static record group 1. true or false?
False

241. What third party tools can be used with Oracle EBU/ RMAN? (for DBA)
The following Media Management Software Vendors have integrated their media management software packages with Oracle Recovery Manager and Oracle7 Enterprise Backup Utility. The Media Management Vendors will provide first line technical support for the integrated backup/recover solutions.
Veritas NetBackup
EMC Data Manager (EDM)
HP OMNIBack II
IBM's Tivoli Storage Manager - formerly ADSM
Legato Networker
ManageIT Backup and Recovery
Sterling Software's SAMS:Alexandria - formerly from Spectralogic
Sun Solstice Backup

242. Why and when should one tune? (for DBA)
One of the biggest responsibilities of a DBA is to ensure that the Oracle database is tuned properly. The Oracle RDBMS is highly tunable and allows the database to be monitored and adjusted to increase its performance. One should do performance tuning for the following reasons:
The speed of computing might be wasting valuable human time (users waiting for response); Enable your system to keep-up with the speed business is conducted; and Optimize hardware usage to save money (companies are spending millions on hardware). Although this FAQ is not overly concerned with hardware issues, one needs to remember than you cannot tune a Buick into a Ferrari.

243. How can a break order be created on a column in an existing group? What are the various sub events a mouse double click event involves?
By dragging the column outside the group.

244. What is the use of place holder column? What are the various sub events a mouse double click event involves?
A placeholder column is used to hold calculated values at a specified place rather than allowing is to appear in the actual row where it has to appear.

245. What is the use of hidden column? What are the various sub events a mouse double click event involves?
A hidden column is used to when a column has to embed into boilerplate text.

246. What database aspects should be monitored? (for DBA)
One should implement a monitoring system to constantly monitor the following aspects of a database. Writing custom scripts, implementing Oracle's Enterprise Manager, or buying a third-party monitoring product can achieve this. If an alarm is triggered, the system should automatically notify the DBA (e-mail, page, etc.) to take appropriate action.
Infrastructure availability:
. Is the database up and responding to requests
. Are the listeners up and responding to requests
. Are the Oracle Names and LDAP Servers up and responding to requests
. Are the Web Listeners up and responding to requests

Things that can cause service outages:
. Is the archive log destination filling up?
. Objects getting close to their max extents
. User and process limits reached

Things that can cause bad performance:
See question "What tuning indicators can one use?".

247. Where should the tuning effort be directed? (for DBA)
Consider the following areas for tuning. The order in which steps are listed needs to be maintained to prevent tuning side effects. For example, it is no good increasing the buffer cache if you can reduce I/O by rewriting a SQL statement. Database Design (if it's not too late):
Poor system performance usually results from a poor database design. One should generally normalize to the 3NF. Selective denormalization can provide valuable performance improvements. When designing, always keep the "data access path" in mind. Also look at proper data partitioning, data replication, aggregation tables for decision support systems, etc.
Application Tuning:
Experience showed that approximately 80% of all Oracle system performance problems are resolved by coding optimal SQL. Also consider proper scheduling of batch tasks after peak working hours.
Memory Tuning:
Properly size your database buffers (shared pool, buffer cache, log buffer, etc) by looking at your buffer hit ratios. Pin large objects into memory to prevent frequent reloads.
Disk I/O Tuning:
Database files needs to be properly sized and placed to provide maximum disk subsystem throughput. Also look for frequent disk sorts, full table scans, missing indexes, row chaining, data fragmentation, etc
Eliminate Database Contention:
Study database locks, latches and wait events carefully and eliminate where possible. Tune the Operating System:
Monitor and tune operating system CPU, I/O and memory utilization. For more information, read the related Oracle FAQ dealing with your specific operating system.

248. What are the various sub events a mouse double click event involves? What are the various sub events a mouse double click event involves?
Double clicking the mouse consists of the mouse down, mouse up, mouse click, mouse down & mouse up events.

249. What are the default parameter that appear at run time in the parameter screen? What are the various sub events a mouse double click event involves?
Destype and Desname.

250. What are the built-ins used for Creating and deleting groups?
CREATE-GROUP (function)
CREATE_GROUP_FROM_QUERY(function)
DELETE_GROUP(procedure)

251. What are different types of canvas views?
Content canvas views
Stacked canvas views
Horizontal toolbar
vertical toolbar.

252. What are the different types of Delete details we can establish in Master-Details?
Cascade
Isolate
Non-isolate

253. What is relation between the window and canvas views?
Canvas views are the back ground objects on which you place the interface items (Text items), check boxes, radio groups etc.,) and boilerplate objects (boxes, lines, images etc.,) that operators interact with us they run your form . Each canvas views displayed in a window.

254. What is a User_exit?
Calls the user exit named in the user_exit_string. Invokes a 3Gl program by name which has been properly linked into your current oracle forms executable.

255. How is it possible to select generate a select set for the query in the query property sheet?
By using the tables/columns button and then specifying the table and the column names.

256. How can values be passed bet. precompiler exits & Oracle call interface?
By using the statement EXECIAFGET & EXECIAFPUT.

257. How can a square be drawn in the layout editor of the report writer?
By using the rectangle tool while pressing the (Constraint) key.

258. How can a text file be attached to a report while creating in the report writer?
By using the link file property in the layout boiler plate property sheet.

259. How can I message to passed to the user from reports?
By using SRW.MESSAGE function.

260. Does one need to drop/ truncate objects before importing? (for DBA)
Before one import rows into already populated tables, one needs to truncate or drop these tables to get rid of the old data. If not, the new data will be appended to the existing tables. One must always DROP existing Sequences before re-importing. If the sequences are not dropped, they will generate numbers inconsistent with the rest of the database. Note: It is also advisable to drop indexes before importing to speed up the import process. Indexes can easily be recreated after the data was successfully imported.

261. How can a button be used in a report to give a drill down facility?
By setting the action associated with button to Execute pl/sql option and using the SRW.Run_report function.

262. Can one import/export between different versions of Oracle? (for DBA)
Different versions of the import utility is upwards compatible. This means that one can take an export file created from an old export version, and import it using a later version of the import utility. This is quite an effective way of upgrading a database from one release of Oracle to the next.
Oracle also ships some previous catexpX.sql scripts that can be executed as user SYS enabling older imp/exp versions to work (for backwards compatibility). For example, one can run $ORACLE_HOME/rdbms/admin/catexp7.sql on an Oracle 8 database to allow the Oracle 7.3 exp/imp utilities to run against an Oracle 8 database.

263. What are different types of images?
Boiler plate imagesImage Items

264. Can one export to multiple files?/ Can one beat the Unix 2 Gig limit? (for DBA)
From Oracle8i, the export utility supports multiple output files. This feature enables large exports to be divided into files whose sizes will not exceed any operating system limits (FILESIZE= parameter). When importing from multi-file export you must provide the same filenames in the same sequence in the FILE= parameter. Look at this example:
exp SCOTT/TIGER FILE=D:\F1.dmp,E:\F2.dmp FILESIZE=10m LOG=scott.log
Use the following technique if you use an Oracle version prior to 8i:
Create a compressed export on the fly. Depending on the type of data, you probably can export up to 10 gigabytes to a single file. This example uses gzip. It offers the best compression I know of, but you can also substitute it with zip, compress or whatever.
# create a named pipe
mknod exp.pipe p
# read the pipe - output to zip file in the background
gzip < exp.pipe > scott.exp.gz &
# feed the pipe
exp userid=scott/tiger file=exp.pipe ...

265. What is bind reference and how can it be created?
Bind reference are used to replace the single value in sql, pl/sql statements a bind reference can be created using a (:) before a column or a parameter name.

266. How can one improve Import/ Export performance? (for DBA)
EXPORT:

. Set the BUFFER parameter to a high value (e.g. 2M)
. Set the RECORDLENGTH parameter to a high value (e.g. 64K)
. Stop unnecessary applications to free-up resources for your job.
. If you run multiple export sessions, ensure they write to different physical disks.
. DO NOT export to an NFS mounted filesystem. It will take forever.
IMPORT:

. Create an indexfile so that you can create indexes AFTER you have imported data. Do this by setting INDEXFILE to a filename and then import. No data will be imported but a file containing index definitions will be created. You must edit this file afterwards and supply the passwords for the schemas on all CONNECT statements.
. Place the file to be imported on a separate physical disk from the oracle data files
. Increase DB_CACHE_SIZE (DB_BLOCK_BUFFERS prior to 9i) considerably in the init$SID.ora file
. Set the LOG_BUFFER to a big value and restart oracle.
. Stop redo log archiving if it is running (ALTER DATABASE NOARCHIVELOG;)
. Create a BIG tablespace with a BIG rollback segment inside. Set all other rollback segments offline (except the SYSTEM rollback segment of course). The rollback segment must be as big as your biggest table (I think?)
. Use COMMIT=N in the import parameter file if you can afford it
. Use ANALYZE=N in the import parameter file to avoid time consuming ANALYZE statements
. Remember to run the indexfile previously created

267. Give the sequence of execution of the various report triggers?
Before form , After form , Before report, Between page, After report.

268. What are the common Import/ Export problems? (for DBA )
ORA-00001: Unique constraint (...) violated - You are importing duplicate rows. Use IGNORE=NO to skip tables that already exist (imp will give an error if the object is re-created).
ORA-01555: Snapshot too old - Ask your users to STOP working while you are exporting or use parameter CONSISTENT=NO
ORA-01562: Failed to extend rollback segment - Create bigger rollback segments or set parameter COMMIT=Y while importing
IMP-00015: Statement failed ... object already exists... - Use the IGNORE=Y import parameter to ignore these errors, but be careful as you might end up with duplicate rows.

269. Why is it preferable to create a fewer no. of queries in the data model?
Because for each query, report has to open a separate cursor and has to rebind, execute and fetch data.

270. Where is the external query executed at the client or the server?
At the server.

271. Where is a procedure return in an external pl/sql library executed at the client or at the server?
At the client.

272. What is coordination Event?
Any event that makes a different record in the master block the current record is a coordination causing event.

273. What is the difference between OLE Server & Ole Container?
An Ole server application creates ole Objects that are embedded or linked in ole Containers ex. Ole servers are ms_word & ms_excel. OLE containers provide a place to store, display and manipulate objects that are created by ole server applications. Ex. oracle forms is an example of an ole Container.

274. What is an object group?
An object group is a container for a group of objects; you define an object group when you want to package related objects, so that you copy or reference them in other modules.

275. What is an LOV?
An LOV is a scrollable popup window that provides the operator with either a single or multi column selection list.

276. At what point of report execution is the before Report trigger fired?
After the query is executed but before the report is executed and the records are displayed.

277. What are the built -ins used for Modifying a groups structure?
ADD-GROUP_COLUMN (function)
ADD_GROUP_ROW (procedure)
DELETE_GROUP_ROW(procedure)

278. What is an user exit used for?
A way in which to pass control (and possibly arguments ) form Oracle report to another Oracle products of 3 GL and then return control ( and ) back to Oracle reports.

279. What is the User-Named Editor?
A user named editor has the same text editing functionality as the default editor, but, because it is a named object, you can specify editor attributes such as windows display size, position, and title.

280. My database was terminated while in BACKUP MODE, do I need to recover? (for DBA)
If a database was terminated while one of its tablespaces was in BACKUP MODE (ALTER TABLESPACE xyz BEGIN BACKUP;), it will tell you that media recovery is required when you try to restart the database. The DBA is then required to recover the database and apply all archived logs to the database. However, from Oracle7.2, you can simply take the individual datafiles out of backup mode and restart the database.
ALTER DATABASE DATAFILE '/path/filename' END BACKUP;
One can select from V$BACKUP to see which datafiles are in backup mode. This normally saves a significant amount of database down time.
Thiru Vadivelu contributed the following:
From Oracle9i onwards, the following command can be used to take all of the datafiles out of hot backup mode:
ALTER DATABASE END BACKUP;
The above commands need to be issued when the database is mounted.

281. What is a Static Record Group?
A static record group is not associated with a query, rather, you define its structure and row values at design time, and they remain fixed at runtime.

282. What is a record group?
A record group is an internal Oracle Forms that structure that has a column/row framework similar to a database table. However, unlike database tables, record groups are separate objects that belong to the form module which they are defined.

283. My database is down and I cannot restore. What now? (for DBA )
Recovery without any backup is normally not supported, however, Oracle Consulting can sometimes extract data from an offline database using a utility called DUL (Disk UnLoad). This utility reads data in the data files and unloads it into SQL*Loader or export dump files. DUL does not care about rollback segments, corrupted blocks, etc, and can thus not guarantee that the data is not logically corrupt. It is intended as an absolute last resort and will most likely cost your company a lot of money!!!

284. I've lost my REDOLOG files, how can I get my DB back? (for DBA)
The following INIT.ORA parameter may be required if your current redo logs are corrupted or blown away. Caution is advised when enabling this parameter as you might end-up losing your entire database. Please contact Oracle Support before using it. _allow_resetlogs_corruption = true

285. What is a property clause?
A property clause is a named object that contains a list of properties and their settings. Once you create a property clause you can base other object on it. An object based on a property can inherit the setting of any property in the clause that makes sense for that object.

286. What is a physical page ? & What is a logical page ?
A physical page is a size of a page. That is output by the printer. The logical page is the size of one page of the actual report as seen in the Previewer.

287. I've lost some Rollback Segments, how can I get my DB back? (for DBA)
Re-start your database with the following INIT.ORA parameter if one of your rollback segments is corrupted. You can then drop the corrupted rollback segments and create it from scratch.
Caution is advised when enabling this parameter, as uncommitted transactions will be marked as committed. One can very well end up with lost or inconsistent data!!! Please contact Oracle Support before using it. _Corrupted_rollback_segments = (rbs01, rbs01, rbs03, rbs04)

288. What are the differences between EBU and RMAN? (for DBA)
Enterprise Backup Utility (EBU) is a functionally rich, high performance interface for backing up Oracle7 databases. It is sometimes referred to as OEBU for Oracle Enterprise Backup Utility. The Oracle Recovery Manager (RMAN) utility that ships with Oracle8 and above is similar to Oracle7's EBU utility. However, there is no direct upgrade path from EBU to RMAN.

289. How does one create a RMAN recovery catalog? (for DBA)
Start by creating a database schema (usually called rman). Assign an appropriate tablespace to it and grant it the recovery_catalog_owner role. Look at this example:
sqlplus sys
SQL>create user rman identified by rman;
SQL> alter user rman default tablespace tools temporary tablespace temp;
SQL> alter user rman quota unlimited on tools;
SQL> grant connect, resource, recovery_catalog_owner to rman;
SQL> exit;
Next, log in to rman and create the catalog schema. Prior to Oracle 8i this was done by running the catrman.sql script. rman catalog rman/rman
RMAN>create catalog tablespace tools;
RMAN> exit;
You can now continue by registering your databases in the catalog. Look at this example:
rman catalog rman/rman target backdba/backdba
RMAN> register database;

290. How can a group in a cross products be visually distinguished from a group that does not form a cross product?
A group that forms part of a cross product will have a thicker border.

291. What is the frame & repeating frame?
A frame is a holder for a group of fields. A repeating frame is used to display a set of records when the no. of records that are to displayed is not known before.

292. What is a combo box?
A combo box style list item combines the features found in list and text item. Unlike the pop list or the text list style list items, the combo box style list item will both display fixed values and accept one operator entered value.

293. What are three panes that appear in the run time pl/sql interpreter?
1. Source pane.
2. interpreter pane.
3. Navigator pane.

294. What are the two panes that Appear in the design time pl/sql interpreter?
1. Source pane.
2. Interpreter pane

295. What are the two ways by which data can be generated for a parameters list of values?
1. Using static values.
2. Writing select statement.

296. What are the various methods of performing a calculation in a report ?
1. Perform the calculation in the SQL statements itself.
2. Use a calculated / summary column in the data model.

297. What are the default extensions of the files created by menu module?
.mmb,
.mmx

298. What are the default extensions of the files created by forms modules?
.fmb - form module binary
.fmx - form module executable

299. To display the page no. for each page on a report what would be the source & logical page no. or & of physical page no.?
& physical page no.

300. It is possible to use raw devices as data files and what is the advantages over file. system files ?
Yes. The advantages over file system files. I/O will be improved because Oracle is bye-passing the kernnel which writing into disk. Disk Corruption will be very less.

301. What are disadvantages of having raw devices ?
We should depend on export/import utility for backup/recovery (fully reliable) The tar command cannot be used for physical file backup, instead we can use dd command which is less flexible and has limited recoveries.

302. What is the significance of having storage clause ?
We can plan the storage for a table as how much initial extents are required, how much can be extended next, how much % should leave free for managing row updations etc.,

303. What is the use of INCTYPE option in EXP command ?
Type export should be performed COMPLETE,CUMULATIVE,INCREMENTAL. List the sequence of events when a large transaction that exceeds beyond its optimal value when an entry wraps and causes the rollback segment toexpand into anotion Completes. e. will be written.

304. What is the use of FILE option in IMP command ?
The name of the file from which import should be performed.

305. What is a Shared SQL pool?
The data dictionary cache is stored in an area in SGA called the Shared SQL Pool. This will allow sharing of parsed SQL statements among concurrent users.

306. What is hot backup and how it can be taken?
Taking backup of archive log files when database is open. For this the ARCHIVELOG mode should be enabled. The following files need to be backed up. All data files. All Archive log, redo log files. All control files.

307. List the Optional Flexible Architecture (OFA) of Oracle database? or How can we organize the tablespaces in Oracle database to have maximum performance ?
SYSTEM - Data dictionary tables.
DATA - Standard operational tables.
DATA2- Static tables used for standard operations
INDEXES - Indexes for Standard operational tables.
INDEXES1 - Indexes of static tables used for standard operations.
TOOLS - Tools table.
TOOLS1 - Indexes for tools table.
RBS - Standard Operations Rollback Segments,
RBS1,RBS2 - Additional/Special Rollback segments.
TEMP - Temporary purpose tablespace
TEMP_USER - Temporary tablespace for users.
USERS - User tablespace.

308. How to implement the multiple control files for an existing database ?
Shutdown the database Copy one of the existing control file to new location Edit Config ora file by adding new control file. name Restart the database.

309. What is advantage of having disk shadowing/ Mirroring ?
Shadow set of disks save as a backup in the event of disk failure. In most Operating System if any disk failure occurs it automatically switchover to place of failed disk. Improved performance because most OS support volume shadowing can direct file I/O request to use the shadow set of files instead of the main set of files. This reduces I/O load on the main set of disks.

310. How will you force database to use particular rollback segment ?
SET TRANSACTION USE ROLLBACK SEGMENT rbs_name.

311. Why query fails sometimes ?
Rollback segment dynamically extent to handle larger transactions entry loads. A single transaction may wipeout all available free space in the Rollback Segment Tablespace. This prevents other user using Rollback segments.

312. What is the use of RECORD LENGTH option in EXP command ?
Record length in bytes.

313. How will you monitor rollback segment status ?
Querying the DBA_ROLLBACK_SEGS view
IN USE - Rollback Segment is on-line.
AVAILABLE - Rollback Segment available but not on-line.
OFF-LINE - Rollback Segment off-line
INVALID - Rollback Segment Dropped.
NEEDS RECOVERY - Contains data but need recovery or corupted.
PARTLY AVAILABLE - Contains data from an unresolved transaction involving a distributed database.

314. What is meant by Redo Log file mirroring ? How it can be achieved?
Process of having a copy of redo log files is called mirroring. This can be achieved by creating group of log files together, so that LGWR will automatically writes them to all the members of the current on-line redo log group. If any one group fails then database automatically switch over to next group. It degrades performance.

315. Which parameter in Storage clause will reduce no. of rows per block?
PCTFREE parameter
Row size also reduces no of rows per block.

316. What is meant by recursive hints ?
Number of times processes repeatedly query the dictionary table is called recursive hints. It is due to the data dictionary cache is too small. By increasing the SHARED_POOL_SIZE parameter we can optimize the size of Data Dictionary Cache.

317. What is the use of PARFILE option in EXP command ?
Name of the parameter file to be passed for export.

318. What is the difference between locks, latches, enqueues and semaphores? (for DBA)
A latch is an internal Oracle mechanism used to protect data structures in the SGA from simultaneous access. Atomic hardware instructions like TEST-AND-SET is used to implement latches. Latches are more restrictive than locks in that they are always exclusive. Latches are never queued, but will spin or sleep until they obtain a resource, or time out.
Enqueues and locks are different names for the same thing. Both support queuing and concurrency. They are queued and serviced in a first-in-first-out (FIFO) order.
Semaphores are an operating system facility used to control waiting. Semaphores are controlled by the following Unix parameters: semmni, semmns and semmsl. Typical settings are:
semmns = sum of the "processes" parameter for each instance
(see init<instance>.ora for each instance)
semmni = number of instances running simultaneously;
semmsl = semmns

319. What is a logical backup?
Logical backup involves reading a set of database records and writing them into a file. Export utility is used for taking backup and Import utility is used to recover from backup.

320. Where can one get a list of all hidden Oracle parameters? (for DBA)
Oracle initialization or INIT.ORA parameters with an underscore in front are hidden or unsupported parameters. One can get a list of all hidden parameters by executing this query:
select *
from SYS.X$KSPPI
where substr(KSPPINM,1,1) = '_';
The following query displays parameter names with their current value:
select a.ksppinm "Parameter", b.ksppstvl "Session Value", c.ksppstvl "Instance Value"
from x$ksppi a, x$ksppcv b, x$ksppsv c
where a.indx = b.indx and a.indx = c.indx
and substr(ksppinm,1,1)='_'
order by a.ksppinm;
Remember: Thou shall not play with undocumented parameters!

321. What is a database EVENT and how does one set it? (for DBA)
Oracle trace events are useful for debugging the Oracle database server. The following two examples are simply to demonstrate syntax. Refer to later notes on this page for an explanation of what these particular events do.
Either adding them to the INIT.ORA parameter file can activate events. E.g.
event='1401 trace name errorstack, level 12'
... or, by issuing an ALTER SESSION SET EVENTS command: E.g.
alter session set events '10046 trace name context forever, level 4';
The alter session method only affects the user's current session, whereas changes to the INIT.ORA file will affect all sessions once the database has been restarted.

322. What is a Rollback segment entry ?
It is the set of before image data blocks that contain rows that are modified by a transaction. Each Rollback Segment entry must be completed within one rollback segment. A single rollback segment can have multiple rollback segment entries.

323. What database events can be set? (for DBA)
The following events are frequently used by DBAs and Oracle Support to diagnose problems:
" 10046 trace name context forever, level 4 Trace SQL statements and show bind variables in trace output.
" 10046 trace name context forever, level 8 This shows wait events in the SQL trace files
" 10046 trace name context forever, level 12 This shows both bind variable names and wait events in the SQL trace files
" 1401 trace name errorstack, level 12 1401 trace name errorstack, level 4 1401 trace name processstate Dumps out trace information if an ORA-1401 "inserted value too large for column" error occurs. The 1401 can be replaced by any other Oracle Server error code that you want to trace.
" 60 trace name errorstack level 10 Show where in the code Oracle gets a deadlock (ORA-60), and may help to diagnose the problem.
The following lists of events are examples only. They might be version specific, so please call Oracle before using them:
" 10210 trace name context forever, level 10 10211 trace name context forever, level 10 10231 trace name context forever, level 10 These events prevent database block corruptions
" 10049 trace name context forever, level 2 Memory protect cursor
" 10210 trace name context forever, level 2 Data block check
" 10211 trace name context forever, level 2 Index block check
" 10235 trace name context forever, level 1 Memory heap check
" 10262 trace name context forever, level 300 Allow 300 bytes memory leak for connections
Note: You can use the Unix oerr command to get the description of an event. On Unix, you can type "oerr ora 10053" from the command prompt to get event details.

324. How can one dump internal database structures? (for DBA)
The following (mostly undocumented) commands can be used to obtain information about internal database structures.
o Dump control file contents
alter session set events 'immediate trace name CONTROLF level 10'
/
o Dump file headers
alter session set events 'immediate trace name FILE_HDRS level 10'
/
o Dump redo log headers
alter session set events 'immediate trace name REDOHDR level 10'
/
o Dump the system state
NOTE: Take 3 successive SYSTEMSTATE dumps, with 10-minute intervals alter session set events 'immediate trace name SYSTEMSTATE level 10'
/
o Dump the process state
alter session set events 'immediate trace name PROCESSSTATE level 10'
/
o Dump Library Cache details
alter session set events 'immediate trace name library cache level 10'
/
o Dump optimizer statistics whenever a SQL statement is parsed (hint: change statement or flush pool) alter session set events '10053 trace name context forever, level 1'
/
o Dump a database block (File/ Block must be converted to DBA address) Convert file and block number to a DBA (database block address).
Eg: variable x varchar2;
exec :x := dbms_utility.make_data_block_address(1,12);
print x
alter session set events 'immediate trace name blockdump level 50360894'
/

325. What are the different kind of export backups?
Full back - Complete database
Incremental - Only affected tables from last incremental date/full backup date.
Cumulative backup - Only affected table from the last cumulative date/full backup date.

326. How free extents are managed in Ver 6.0 and Ver 7.0 ?
Free extents cannot be merged together in Ver 6.0.
Free extents are periodically coalesces with the neighboring free extent in Ver 7.0

327. What is the use of RECORD option in EXP command?
For Incremental exports, the flag indirects whether a record will be stores data dictionary tables recording the export.

328. What is Auditing ?
The database has the ability to audit all actions that take place within it.
a) Login attempts, b) Object Accesss, c) Database Action Result of Greatest(1,NULL) or Least(1,NULL) NULL

329. While designing in client/server what are the 2 imp. things to be considered ?
Network Overhead (traffic), Speed and Load of client server

330. When to create indexes ?
To be created when table is queried for less than 2% or 4% to 25% of the table rows.

331. How can you avoid indexes ?
TO make index access path unavailable - Use FULL hint to optimizer for full table scan - Use INDEX or AND-EQUAL hint to optimizer to use one index or set to indexes instead of another. - Use an expression in the Where Clause of the SQL.

332. What is the result of the following SQL :
Select 1 from dual
UNION
Select 'A' from dual;
Error

333. Can database trigger written on synonym of a table and if it can be then what would be the effect if original table is accessed.
Yes, database trigger would fire.

334. Can you alter synonym of view or view ?
No

335. Can you create index on view ?
No

336. What is the difference between a view and a synonym ?
Synonym is just a second name of table used for multiple link of database. View can be created with many tables, and with virtual columns and with conditions. But synonym can be on view.

337. What is the difference between alias and synonym ?
Alias is temporary and used with one query. Synonym is permanent and not used as alias.

338. What is the effect of synonym and table name used in same Select statement ?
Valid

339. What's the length of SQL integer ?
32 bit length

340. What is the difference between foreign key and reference key ?
Foreign key is the key i.e. attribute which refers to another table primary key. Reference key is the primary key of table referred by another table.

341. Can dual table be deleted, dropped or altered or updated or inserted ?
Yes

342. If content of dual is updated to some value computation takes place or not ?
Yes

343. If any other table same as dual is created would it act similar to dual?
Yes

344. For which relational operators in where clause, index is not used ?
<> , like '% ...' is NOT functions, field +constant, field || ''

345. Assume that there are multiple databases running on one machine. How can you switch from one to another ?
Changing the ORACLE_SID

346. What are the advantages of Oracle ?
Portability : Oracle is ported to more platforms than any of its competitors, running on more than 100 hardware platforms and 20 networking protocols.
Market Presence : Oracle is by far the largest RDBMS vendor and spends more on R & D than most of its competitors earn in total revenue. This market clout means that you are unlikely to be left in the lurch by Oracle and there are always lots of third party interfaces available.
Backup and Recovery : Oracle provides industrial strength support for on-line backup and recovery and good software fault tolerence to disk failure. You can also do point-in-time recovery.
Performance : Speed of a 'tuned' Oracle Database and application is quite good, even with large databases. Oracle can manage > 100GB databases.
Multiple database support : Oracle has a superior ability to manage multiple databases within the same transaction using a two-phase commit protocol.

347. What is a forward declaration ? What is its use ?
PL/SQL requires that you declare an identifier before using it. Therefore, you must declare a subprogram before calling it. This declaration at the start of a subprogram is called forward declaration. A forward declaration consists of a subprogram specification terminated by a semicolon.

348. What are actual and formal parameters ?
Actual Parameters : Subprograms pass information using parameters. The variables or expressions referenced in the parameter list of a subprogram call are actual parameters. For example, the following procedure call lists two actual parameters named emp_num and amount:
Eg. raise_salary(emp_num, amount);
Formal Parameters : The variables declared in a subprogram specification and referenced in the subprogram body are formal parameters. For example, the following procedure declares two formal parameters named emp_id and increase: Eg. PROCEDURE raise_salary (emp_id INTEGER, increase REAL) IS current_salary REAL;

349. What are the types of Notation ?
Position, Named, Mixed and Restrictions.

350. What all important parameters of the init.ora are supposed to be increased if you want to increase the SGA size ?
In our case, db_block_buffers was changed from 60 to 1000 (std values are 60, 550 & 3500) shared_pool_size was changed from 3.5MB to 9MB (std values are 3.5, 5 & 9MB) open_cursors was changed from 200 to 300 (std values are 200 & 300) db_block_size was changed from 2048 (2K) to 4096 (4K) {at the time of database creation}.
The initial SGA was around 4MB when the server RAM was 32MB and The new SGA was around 13MB when the server RAM was increased to 128MB.

351. If I have an execute privilege on a procedure in another users schema, can I execute his procedure even though I do not have privileges on the tables within the procedure ?
Yes

352. What are various types of joins ?
Equijoins, Non-equijoins, self join, outer join

353. What is a package cursor ?
A package cursor is a cursor which you declare in the package specification without an SQL statement. The SQL statement for the cursor is attached dynamically at runtime from calling procedures.

354. If you insert a row in a table, then create another table and then say Rollback. In this case will the row be inserted ?
Yes. Because Create table is a DDL which commits automatically as soon as it is executed. The DDL commits the transaction even if the create statement fails internally (eg table already exists error) and not syntactically.

355. What are the various types of queries ??
Normal Queries
Sub Queries
Co-related queries
Nested queries
Compound queries

356. What is a transaction ?
A transaction is a set of SQL statements between any two COMMIT and ROLLBACK statements.

357. What is implicit cursor and how is it used by Oracle ?
An implicit cursor is a cursor which is internally created by Oracle. It is created by Oracle for each individual SQL.

358. Which of the following is not a schema object : Indexes, tables, public synonyms, triggers and packages ?
Public synonyms

359. What is PL/SQL?
PL/SQL is Oracle's Procedural Language extension to SQL. The language includes object oriented programming techniques such as encapsulation, function overloading, information hiding (all but inheritance), and so, brings state-of-the-art programming to the Oracle database server and a variety of Oracle tools.

360. Is there a PL/SQL Engine in SQL*Plus?
No. Unlike Oracle Forms, SQL*Plus does not have a PL/SQL engine. Thus, all your PL/SQL are send directly to the database engine for execution. This makes it much more efficient as SQL statements are not stripped off and send to the database individually.

361. Is there a limit on the size of a PL/SQL block?
Currently, the maximum parsed/compiled size of a PL/SQL block is 64K and the maximum code size is 100K. You can run the following select statement to query the size of an existing package or procedure.
SQL> select * from dba_object_size where name = 'procedure_name'

362. Can one read/write files from PL/SQL?
Included in Oracle 7.3 is a UTL_FILE package that can read and write files. The directory you intend writing to has to be in your INIT.ORA file (see UTL_FILE_DIR=... parameter). Before Oracle 7.3 the only means of writing a file was to use DBMS_OUTPUT with the SQL*Plus SPOOL command.
DECLARE
fileHandler UTL_FILE.FILE_TYPE;
BEGIN
fileHandler := UTL_FILE.FOPEN('/home/oracle/tmp', 'myoutput','W');
UTL_FILE.PUTF(fileHandler, 'Value of func1 is %sn', func1(1));
UTL_FILE.FCLOSE(fileHandler);
END;

363. How can I protect my PL/SQL source code?
PL/SQL V2.2, available with Oracle7.2, implements a binary wrapper for PL/SQL programs to protect the source code. This is done via a standalone utility that transforms the PL/SQL source code into portable binary object code (somewhat larger than the original). This way you can distribute software without having to worry about exposing your proprietary algorithms and methods. SQL*Plus and SQL*DBA will still understand and know how to execute such scripts. Just be careful, there is no "decode" command available.
The syntax is:
wrap iname=myscript.sql oname=xxxx.yyy

364. Can one use dynamic SQL within PL/SQL? OR Can you use a DDL in a procedure ? How ?
From PL/SQL V2.1 one can use the DBMS_SQL package to execute dynamic SQL statements.
Eg: CREATE OR REPLACE PROCEDURE DYNSQL
AS
cur integer;
rc integer;
BEGIN
cur := DBMS_SQL.OPEN_CURSOR;
DBMS_SQL.PARSE(cur,'CREATE TABLE X (Y DATE)', DBMS_SQL.NATIVE);
rc := DBMS_SQL.EXECUTE(cur);
DBMS_SQL.CLOSE_CURSOR(cur);
END;

365. What is the advantage of a stored procedure over a database trigger ?
We have control over the firing of a stored procedure but we have no control over the firing of a trigger.

366. What is the maximum no. of statements that can be specified in a trigger statement ?
One.

367. Can views be specified in a trigger statement ?
No

368. What are the values of :new and :old in Insert/Delete/Update Triggers ?
INSERT : new = new value, old = NULL
DELETE : new = NULL, old = old value
UPDATE : new = new value, old = old value

369. What are cascading triggers? What is the maximum no of cascading triggers at a time?
When a statement in a trigger body causes another trigger to be fired, the triggers are said to be cascading. Max = 32.

370. What are mutating triggers ?
A trigger giving a SELECT on the table on which the trigger is written.

371. What are constraining triggers ?
A trigger giving an Insert/Update on a table having referential integrity constraint on the triggering table.

372. Describe Oracle database's physical and logical structure ?
Physical : Data files, Redo Log files, Control file.
Logical : Tables, Views, Tablespaces, etc.

373. Can you increase the size of a tablespace ? How ?
Yes, by adding datafiles to it.

374. What is the use of Control files ?
Contains pointers to locations of various data files, redo log files, etc.

375. What is the use of Data Dictionary ?
Used by Oracle to store information about various physical and logical Oracle structures e.g. Tables, Tablespaces, datafiles, etc

376. What are the advantages of clusters ?
Access time reduced for joins.

377. What are the disadvantages of clusters ?
The time for Insert increases.

378. Can Long/Long RAW be clustered ?
No.

379. Can null keys be entered in cluster index, normal index ?
Yes.

380. Can Check constraint be used for self referential integrity ? How ?
Yes. In the CHECK condition for a column of a table, we can reference some other column of the same table and thus enforce self referential integrity.

381. What are the min. extents allocated to a rollback extent ?
Two

382. What are the states of a rollback segment ? What is the difference between partly available and needs recovery ?
The various states of a rollback segment are :
ONLINE, OFFLINE, PARTLY AVAILABLE, NEEDS RECOVERY and INVALID.

383. What is the difference between unique key and primary key ?
Unique key can be null; Primary key cannot be null.

384. An insert statement followed by a create table statement followed by rollback ? Will the rows be inserted ?
No.

385. an you define multiple savepoints ?
Yes.

386. Can you Rollback to any savepoint ?
Yes.

387. What is the maximum no. of columns a table can have ?
254.

388. What is the significance of the & and && operators in PL SQL ?
The & operator means that the PL SQL block requires user input for a variable. The && operator means that the value of this variable should be the same as inputted by the user previously for this same variable. If a transaction is very large, and the rollback segment is not able to hold the rollback information, then will the transaction span across different rollback segments or will it terminate ? It will terminate (Please check ).

389. Can you pass a parameter to a cursor ?
Explicit cursors can take parameters, as the example below shows. A cursor parameter can appear in a query wherever a constant can appear. CURSOR c1 (median IN NUMBER) IS SELECT job, ename FROM emp WHERE sal > median;

390. What are the various types of RollBack Segments ?
Public Available to all instances
Private Available to specific instance

391. Can you use %RowCount as a parameter to a cursor ?
Yes

392. Is the query below allowed :
Select sal, ename Into x From emp Where ename = 'KING'
(Where x is a record of Number(4) and Char(15))
Yes

393. Is the assignment given below allowed :
ABC = PQR (Where ABC and PQR are records)
Yes

394. Is this for loop allowed :
For x in &Start..&End Loop
Yes

395. How many rows will the following SQL return :
Select * from emp Where rownum < 10;
9 rows

396. How many rows will the following SQL return :
Select * from emp Where rownum = 10;
No rows

397. Which symbol preceeds the path to the table in the remote database ?
@

398. Are views automatically updated when base tables are updated ?
Yes

399. Can a trigger written for a view ?
No

400. If all the values from a cursor have been fetched and another fetch is issued, the output will be : error, last record or first record ?
Last Record

401. A table has the following data : [[5, Null, 10]]. What will the average function return ?
7.5

402. Is Sysdate a system variable or a system function?
System Function

403. Consider a sequence whose currval is 1 and gets incremented by 1 by using the nextval reference we get the next number 2. Suppose at this point we issue an rollback and again issue a nextval. What will the output be ?
3

404. Definition of relational DataBase by Dr. Codd (IBM)?
A Relational Database is a database where all data visible to the user is organized strictly as tables of data values and where all database operations work on these tables.

405. What is Multi Threaded Server (MTA) ?
In a Single Threaded Architecture (or a dedicated server configuration) the database manager creates a separate process for each database user. But in MTA the database manager can assign multiple users (multiple user processes) to a single dispatcher (server process), a controlling process that queues request for work thus reducing the databases memory requirement and resources.

406. Which are initial RDBMS, Hierarchical & N/w database ?
RDBMS - R system
Hierarchical - IMS
N/W - DBTG

407. What is Functional Dependency
Given a relation R, attribute Y of R is functionally dependent on attribute X of R if and only if each X-value has associated with it precisely one -Y value in R

408. What are the triggers available in the reports?
Before report, Before form, After form , Between page, After report.

409. Why is a Where clause faster than a group filter or a format trigger?
Because, in a where clause the condition is applied during data retrievalthan after retrieving the data.

410. Can one selectively load only the records that one need? (for DBA)
Look at this example, (01) is the first character, (30:37) are characters 30 to 37:
LOAD DATA
INFILE 'mydata.dat' BADFILE 'mydata.bad' DISCARDFILE 'mydata.dis'
APPEND
INTO TABLE my_selective_table
WHEN (01) <> 'H' and (01) <> 'T' and (30:37) = '19991217'
(
region CONSTANT '31',
service_key POSITION(01:11) INTEGER EXTERNAL,
call_b_no POSITION(12:29) CHAR
)

411. Can one skip certain columns while loading data? (for DBA)
One cannot use POSTION(x:y) with delimited data. Luckily, from Oracle 8i one can specify FILLER columns. FILLER columns are used to skip columns/fields in the load file, ignoring fields that one does not want. Look at this example: -- One cannot use POSTION(x:y) as it is stream data, there are no positional fields-the next field begins after some delimiter, not in column X. -->
LOAD DATA
TRUNCATE INTO TABLE T1
FIELDS TERMINATED BY ','
( field1,
field2 FILLER,
field3
)

412. How does one load multi-line records? (for DBA)
One can create one logical record from multiple physical records using one of the following two clauses:
. CONCATENATE: - use when SQL*Loader should combine the same number of physical records together to form one logical record.
. CONTINUEIF - use if a condition indicates that multiple records should be treated as one. Eg. by having a '#' character in column 1.

413. How can get SQL*Loader to COMMIT only at the end of the load file? (for DBA)
One cannot, but by setting the ROWS= parameter to a large value, committing can be reduced. Make sure you have big rollback segments ready when you use a high value for ROWS=.

414. Can one improve the performance of SQL*Loader? (for DBA)
A very simple but easily overlooked hint is not to have any indexes and/or constraints (primary key) on your load tables during the load process. This will significantly slow down load times even with ROWS= set to a high value.
Add the following option in the command line: DIRECT=TRUE. This will effectively bypass most of the RDBMS processing. However, there are cases when you can't use direct load. Refer to chapter 8 on Oracle server Utilities manual.
Turn off database logging by specifying the UNRECOVERABLE option. This option can only be used with direct data loads. Run multiple load jobs concurrently.

415. How does one use SQL*Loader to load images, sound clips and documents? (for DBA)
SQL*Loader can load data from a "primary data file", SDF (Secondary Data file - for loading nested tables and VARRAYs) or LOGFILE. The LOBFILE method provides and easy way to load documents, images and audio clips into BLOB and CLOB columns. Look at this example:
Given the following table:
CREATE TABLE image_table (
image_id NUMBER(5),
file_name VARCHAR2(30),
image_data BLOB);
Control File:
LOAD DATA
INFILE *
INTO TABLE image_table
REPLACE
FIELDS TERMINATED BY ','
(
image_id INTEGER(5),
file_name CHAR(30),
image_data LOBFILE (file_name) TERMINATED BY EOF
)
BEGINDATA
001,image1.gif
002,image2.jpg

416. What is the difference between the conventional and direct path loader? (for DBA)
The conventional path loader essentially loads the data by using standard INSERT statements. The direct path loader (DIRECT=TRUE) bypasses much of the logic involved with that, and loads directly into the Oracle data files. More information about the restrictions of direct path loading can be obtained from the Utilities Users Guide.

417. GENERAL INTERVIEW QUESTIONS
What are the various types of Exceptions ?
User defined and Predefined Exceptions.

418. Can we define exceptions twice in same block ?
No.

419. What is the difference between a procedure and a function ?
Functions return a single variable by value whereas procedures do not return any variable by value. Rather they return multiple variables by passing variables by reference through their OUT parameter.

420. Can you have two functions with the same name in a PL/SQL block ?
Yes.

421. Can you have two stored functions with the same name ?
Yes.

422. Can you call a stored function in the constraint of a table ?
No.

423. What are the various types of parameter modes in a procedure ?
IN, OUT AND INOUT.

424. What is Over Loading and what are its restrictions ?
OverLoading means an object performing different functions depending upon the no. of parameters or the data type of the parameters passed to it.

425. Can functions be overloaded ?
Yes.

426. Can 2 functions have same name & input parameters but differ only by return datatype ?
No.

427. What are the constructs of a procedure, function or a package ?
The constructs of a procedure, function or a package are :
variables and constants
cursors
exceptions

428. Why Create or Replace and not Drop and recreate procedures ?
So that Grants are not dropped.

429. Can you pass parameters in packages ? How ?
Yes. You can pass parameters to procedures or functions in a package.

430. What are the parts of a database trigger ?
The parts of a trigger are:
A triggering event or statement
A trigger restriction
A trigger action

431. What are the various types of database triggers ?
There are 12 types of triggers, they are combination of :
Insert, Delete and Update Triggers.
Before and After Triggers.
Row and Statement Triggers.
(3*2*2=12)

432. Explain UNION,MINUS,UNION ALL, INTERSECT ?
INTERSECT returns all distinct rows selected by both queries.MINUS - returns all distinct rows selected by the first query but not by the second.UNION - returns all distinct rows selected by either queryUNION ALL - returns all rows selected by either query, including all duplicates.

433. Should the OEM Console be displayed at all times (when there are scheduled jobs)? (for DBA)
When a job is submitted the agent will confirm the status of the job. When the status shows up as scheduled, you can close down the OEM console. The processing of the job is managed by the OIA (Oracle Intelligent Agent). The OIA maintains a .jou file in the agent's subdirectory. When the console is launched communication with the Agent is established and the contents of the .jou file (binary) are reported to the console job subsystem. Note that OEM will not be able to send e-mail and paging notifications when the Console is not started.

434. Difference between SUBSTR and INSTR ?
INSTR (String1,String2(n,(m)),INSTR returns the position of the mth occurrence of the string 2 instring1. The search begins from nth position of string1.SUBSTR (String1 n,m)SUBSTR returns a character string of size m in string1, starting from nth position of string1.

435. What kind of jobs can one schedule with OEM? (for DBA)
OEM comes with pre-defined jobs like Export, Import, run OS commands, run sql scripts, SQL*Plus commands etc. It also gives you the flexibility of scheduling custom jobs written with the TCL language.

436. What are the pre requisites ?
I. to modify data type of a column ? ii. to add a column with NOT NULL constraint ? To Modify the datatype of a column the column must be empty. to add a column with NOT NULL constrain, the table must be empty.

437. How does one backout events and jobs during maintenance slots? (for DBA)
Managemnet and data collection activity can be suspended by imposing a blackout. Look at these examples:
agentctl start blackout # Blackout the entrire agent
agentctl stop blackout # Resume normal monitoring and management
agentctl start blackout ORCL # Blackout database ORCL
agentctl stop blackout ORCL # Resume normal monitoring and management
agentctl start blackout -s jobs -d 00:20 # Blackout jobs for 20 minutes

438. What are the types of SQL Statement ?
Data Definition Language :
CREATE,ALTER,DROP,TRUNCATE,REVOKE,NO AUDIT & COMMIT.

Data Manipulation Language:
INSERT,UPDATE,DELETE,LOCK

TABLE,EXPLAIN PLAN & SELECT.Transactional Control:
COMMIT & ROLLBACKSession Control: ALTERSESSION & SET

ROLESystem Control :
ALTER SYSTEM.

439. What is the Oracle Intelligent Agent? (for DBA)
The Oracle Intelligent Agent (OIA) is an autonomous process that needs to run on a remote node in the network to make the node OEM manageable. The Oracle Intelligent Agent is responsible for:
. Discovering targets that can be managed (Database Servers, Net8 Listeners, etc.);
. Monitoring of events registered in Enterprise Manager; and
. Executing tasks associated with jobs submitted to Enterprise Manager.

440. How does one start the Oracle Intelligent Agent? (for DBA)
One needs to start an OIA (Oracle Intelligent Agent) process on all machines that will to be managed via OEM.
For OEM 9i and above:
agentctl start agent
agentctl stop agent

For OEM 2.1 and below:
lsnrctl dbsnmp_start
lsnrctl dbsnmp_status

On Windows NT, start the "OracleAgent" Service.
If the agent doesn't want to start, ensure your environment variables are set correctly and delete the following files before trying again:
1) In $ORACLE_HOME/network/admin: snmp_ro.ora and snmp_rw.ora.
2) Also delete ALL files in $ORACLE_HOME/network/agent/.

441. Can one write scripts to send alert messages to the console?
Start the OEM console and create a new event. Select option "Enable Unsolicited Event". Select test "Unsolicited Event". When entering the parameters, enter values similar to these:
Event Name: /oracle/script/myalert
Object: *
Severity: *
Message: *
One can now write the script and invoke the oemevent command to send alerts to the console. Look at this example: oemevent /oracle/script/myalert DESTINATION alert "My custom error message" where DESTINATION is the same value as entered in the "Monitored Destinations" field when you've registered the event in the OEM Console.

442. Where can one get more information about TCL? (for DBA)
One can write custom event checking routines for OEM using the TCL (Tool Command Language) language. Check the following sites for more information about TCL:
. The Tcl Developer Xchange - download and learn about TCL
. OraTCL at Sourceforge - Download the OraTCL package
. Tom Poindexter's Tcl Page - Oratcl was originally written by Tom Poindexter

443. Are there any troubleshooting tips for OEM? (for DBA)
. Create the OEM repository with a user (which will manage the OEM) and store it in a tablespace that does not share any data with other database users. It is a bad practice to create the repository with SYS and System.
. If you are unable to launch the console or there is a communication problem with the intelligent agent (daemon). Ensure OCX files are registered. Type the following in the DOS prompt (the current directory should be $ORACLE_HOME\BIN:
C:\Orawin95\Bin> RegSvr32 mmdx32.OCX
C:\Orawin95\Bin> RegSvr32 vojt.OCX
. If you have a problem starting the Oracle Agent
Solution A: Backup the *.Q files and Delete all the *.Q Files ($Oracle_home/network/agent folder)
Backup and delete SNMP_RO.ora, SNMP_RW.ora, dbsnmp.ver and services.ora files ($Oracle_Home/network/admin folder) Start the Oracle Agent service.
Solution B: Your version of Intelligent Agent could be buggy. Check with Oracle for any available patches. For example, the Intelligent Agent that comes with Oracle 8.0.4 is buggy.
Sometimes you get a Failed status for the job that was executed successfully.
Check the log to see the results of the execution rather than relying on this status.

444. What is import/export and why does one need it? (for DBA)
The Oracle export (EXP) and import (IMP) utilities are used to perform logical database backup and recovery. They are also used to move Oracle data from one machine, database or schema to another.
The imp/exp utilities use an Oracle proprietary binary file format and can thus only be used between Oracle databases. One cannot export data and expect to import it into a non-Oracle database. For more information on how to load and unload data from files, read the SQL*Loader FAQ.
The export/import utilities are also commonly used to perform the following tasks:
. Backup and recovery (small databases only)
. Reorganization of data/ Eliminate database fragmentation
. Detect database corruption. Ensure that all the data can be read.
. Transporting tablespaces between databases
. Etc.

445. What is a display item?
Display items are similar to text items but store only fetched or assigned values. Operators cannot navigate to a display item or edit the value it contains.

446. How does one use the import/export utilities? (for DBA)
Look for the "imp" and "exp" executables in your $ORACLE_HOME/bin directory. One can run them interactively, using command line parameters, or using parameter files. Look at the imp/exp parameters before starting. These parameters can be listed by executing the following commands: "exp help=yes" or "imp help=yes".
The following examples demonstrate how the imp/exp utilities can be used:
exp scott/tiger file=emp.dmp log=emp.log tables=emp rows=yes indexes=no
exp scott/tiger file=emp.dmp tables=(emp,dept)
imp scott/tiger file=emp.dmp full=yes
imp scott/tiger file=emp.dmp fromuser=scott touser=scott tables=dept
exp userid=scott/tiger@orcl parfile=export.txt
... where export.txt contains:
BUFFER=100000
FILE=account.dmp
FULL=n
OWNER=scott
GRANTS=y
COMPRESS=y
NOTE: If you do not like command line utilities, you can import and export data with the "Schema Manager" GUI that ships with Oracle Enterprise Manager (OEM).

447. What are the types of visual attribute settings?
Custom Visual attributes Default visual attributes Named Visual attributes. Window

448. Can one export a subset of a table? (for DBA)
From Oracle8i one can use the QUERY= export parameter to selectively unload a subset of the data from a table. Look at this example:
exp scott/tiger tables=emp query=\"where deptno=10\"

449. What are the two ways to incorporate images into a oracle forms application?
Boilerplate Images
Image_items

450. Can one monitor how fast a table is imported? (for DBA)
If you need to monitor how fast rows are imported from a running import job, try one of the following methods:
Method 1:
select substr(sql_text,instr(sql_text,'INTO "'),30) table_name,
rows_processed,
round((sysdate-to_date(first_load_time,'yyyy-mm-dd hh24:mi:ss'))*24*60,1) minutes,
trunc(rows_processed/((sysdate-to_date(first_load_time,'yyyy-mm-dd hh24:mi:ss'))*24*60)) rows_per_min
from sys.v_$sqlarea
where sql_text like 'INSERT %INTO "%'
and command_type = 2
and open_versions > 0;
For this to work one needs to be on Oracle 7.3 or higher (7.2 might also be OK). If the import has more than one table, this statement will only show information about the current table being imported.
Contributed by Osvaldo Ancarola, Bs. As. Argentina.
Method 2:
Use the FEEDBACK=n import parameter. This command will tell IMP to display a dot for every N rows imported.

451. Can one import tables to a different tablespace? (for DBA)
Oracle offers no parameter to specify a different tablespace to import data into. Objects will be re-created in the tablespace they were originally exported from. One can alter this behaviour by following one of these procedures: Pre-create the table(s) in the correct tablespace:
. Import the dump file using the INDEXFILE= option
. Edit the indexfile. Remove remarks and specify the correct tablespaces.
. Run this indexfile against your database, this will create the required tables in the appropriate tablespaces
. Import the table(s) with the IGNORE=Y option.
Change the default tablespace for the user:

. Revoke the "UNLIMITED TABLESPACE" privilege from the user
. Revoke the user's quota from the tablespace from where the object was exported. This forces the import utility to create tables in the user's default tablespace.
. Make the tablespace to which you want to import the default tablespace for the user
. Import the table

452. What do you mean by a block in forms4.0?
Block is a single mechanism for grouping related items into a functional unit for storing, displaying and manipulating records.

453. How is possible to restrict the user to a list of values while entering values for parameters?
By setting the Restrict To List property to true in the parameter property sheet.

454. What is SQL*Loader and what is it used for? (for DBA)
SQL*Loader is a bulk loader utility used for moving data from external files into the Oracle database. Its syntax is similar to that of the DB2 Load utility, but comes with more options. SQL*Loader supports various load formats, selective loading, and multi-table loads.

455. How does one use the SQL*Loader utility? (for DBA)
One can load data into an Oracle database by using the sqlldr (sqlload on some platforms) utility. Invoke the utility without arguments to get a list of available parameters. Look at the following example:
sqlldr scott/tiger control=loader.ctl
This sample control file (loader.ctl) will load an external data file containing delimited data:
load data
infile 'c:\data\mydata.csv'
into table emp
fields terminated by "," optionally enclosed by '"'
( empno, empname, sal, deptno )
The mydata.csv file may look like this:
10001,"Scott Tiger", 1000, 40
10002,"Frank Naude", 500, 20
Another Sample control file with in-line data formatted as fix length records. The trick is to specify "*" as the name of the data file, and use BEGINDATA to start the data section in the control file.
load data
infile *
replace
into table departments
( dept position (02:05) char(4),
deptname position (08:27) char(20)
)
begindata
COSC COMPUTER SCIENCE
ENGL ENGLISH LITERATURE
MATH MATHEMATICS
POLY POLITICAL SCIENCE

456. How can a cross product be created?
By selecting the cross products tool and drawing a new group surrounding the base group of the cross products.

457. Is there a SQL*Unloader to download data to a flat file? (for DBA)
Oracle does not supply any data unload utilities. However, you can use SQL*Plus to select and format your data and then spool it to a file:
set echo off newpage 0 space 0 pagesize 0 feed off head off trimspool on
spool oradata.txt
select col1 || ',' || col2 || ',' || col3
from tab1
where col2 = 'XYZ';
spool off
Alternatively use the UTL_FILE PL/SQL package:
rem Remember to update initSID.ora, utl_file_dir='c:\oradata' parameter
declare
fp utl_file.file_type;
begin
fp := utl_file.fopen('c:\oradata','tab1.txt','w');
utl_file.putf(fp, '%s, %s\n', 'TextField', 55);
utl_file.fclose(fp);
end;
/
You might also want to investigate third party tools like SQLWays from Ispirer Systems, TOAD from Quest, or ManageIT Fast Unloader from CA to help you unload data from Oracle.

458. Can one load variable and fix length data records? (for DBA)
Yes, look at the following control file examples. In the first we will load delimited data (variable length):
LOAD DATA
INFILE *
INTO TABLE load_delimited_data
FIELDS TERMINATED BY "," OPTIONALLY ENCLOSED BY '"'
TRAILING NULLCOLS
( data1,
data2
)
BEGINDATA
11111,AAAAAAAAAA
22222,"A,B,C,D,"
If you need to load positional data (fixed length), look at the following control file example:
LOAD DATA
INFILE *
INTO TABLE load_positional_data
( data1 POSITION(1:5),
data2 POSITION(6:15)
)
BEGINDATA
11111AAAAAAAAAA
22222BBBBBBBBBB
Can one skip header records load while loading?
Use the "SKIP n" keyword, where n = number of logical rows to skip. Look at this example:
LOAD DATA
INFILE *
INTO TABLE load_positional_data
SKIP 5
( data1 POSITION(1:5),
data2 POSITION(6:15)
)
BEGINDATA
11111AAAAAAAAAA
22222BBBBBBBBBB

459. Can one modify data as it loads into the database? (for DBA)
Data can be modified as it loads into the Oracle Database. Note that this only applies for the conventional load path and not for direct path loads.
LOAD DATA
INFILE *
INTO TABLE modified_data
( rec_no "my_db_sequence.nextval",
region CONSTANT '31',
time_loaded "to_char(SYSDATE, 'HH24:MI')",
data1 POSITION(1:5) ":data1/100",
data2 POSITION(6:15) "upper(:data2)",
data3 POSITION(16:22)"to_date(:data3, 'YYMMDD')"
)
BEGINDATA
11111AAAAAAAAAA991201
22222BBBBBBBBBB990112
LOAD DATA
INFILE 'mail_orders.txt'
BADFILE 'bad_orders.txt'
APPEND
INTO TABLE mailing_list
FIELDS TERMINATED BY ","
( addr,
city,
state,
zipcode,
mailing_addr "decode(:mailing_addr, null, :addr, :mailing_addr)",
mailing_city "decode(:mailing_city, null, :city, :mailing_city)",
mailing_state
)

460. Can one load data into multiple tables at once? (for DBA)
Look at the following control file:
LOAD DATA
INFILE *
REPLACE
INTO TABLE emp
WHEN empno != ' '
( empno POSITION(1:4) INTEGER EXTERNAL,
ename POSITION(6:15) CHAR,
deptno POSITION(17:18) CHAR,
mgr POSITION(20:23) INTEGER EXTERNAL
)
INTO TABLE proj
WHEN projno != ' '
( projno POSITION(25:27) INTEGER EXTERNAL,
empno POSITION(1:4) INTEGER EXTERNAL
)

461. What is the difference between boiler plat images and image items?
Boiler plate Images are static images (Either vector or bit map) that you import from the file system or database to use a graphical elements in your form, such as company logos and maps. Image items are special types of interface controls that store and display either vector or bitmap images. Like other items that store values, image items can be either base table items(items that relate directly to database columns) or control items. The definition of an image item is stored as part of the form module FMB and FMX files, but no image file is actually associated with an image item until the item is populate at run time.

462. If the maximum record retrieved property of the query is set to 10 then a summary value will be calculated?
Only for 10 records.

463. What are the different objects that you cannot copy or reference in object groups?
Objects of different modules
Another object groups
Individual block dependent items
Program units.

464. What is an OLE?
Object Linking & Embedding provides you with the capability to integrate objects from many Ms-Windows applications into a single compound document creating integrated applications enables you to use the features form .

465. Can a repeating frame be created without a data group as a base?
No

466. Is it possible to set a filter condition in a cross product group in matrix reports?
No

467. What is Overloading of procedures ?
The Same procedure name is repeated with parameters of different datatypes and parameters in different positions, varying number of parameters is called overloading of procedures. e.g. DBMS_OUTPUT put_line

468. What are the return values of functions SQLCODE and SQLERRM ? What is Pragma EXECPTION_INIT ? Explain the usage ?
SQLCODE returns the latest code of the error that has occurred.
SQLERRM returns the relevant error message of the SQLCODE.

469. What are the datatypes a available in PL/SQL ?
Some scalar data types such as NUMBER, VARCHAR2, DATE, CHAR, LONG, BOOLEAN. Some composite data types such as RECORD & TABLE.

470. What are the two parts of a procedure ?
Procedure Specification and Procedure Body.

471. What is the basic structure of PL/SQL ?
PL/SQL uses block structure as its basic structure. Anonymous blocks or nested blocks can be used in PL/SQL

472. What is PL/SQL table ?
Objects of type TABLE are called "PL/SQL tables", which are modeled as (but not the same as) database tables, PL/SQL tables use a primary PL/SQL tables can have one column and a primary key. Cursors

473. WHAT IS RMAN ? (for DBA)
Recovery Manager is a tool that: manages the process of creating backups and also manages the process of restoring and recovering from them.

474. WHY USE RMAN ? (for DBA)
No extra costs …Its available free
?RMAN introduced in Oracle 8 it has become simpler with newer versions and easier than user managed backups
?Proper security
?You are 100% sure your database has been backed up.
?Its contains detail of the backups taken etc in its central repository
Facility for testing validity of backups also commands like crosscheck to check the status of backup.
Faster backups and restores compared to backups without RMAN
RMAN is the only backup tool which supports incremental backups.
Oracle 10g has got further optimized incremental backup which has resulted in improvement of performance during backup and recovery time
Parallel operations are supported
Better querying facility for knowing different details of backup
No extra redo generated when backup is taken..compared to online
backup without RMAN which results in saving of space in hard disk
RMAN an intelligent tool
Maintains repository of backup metadata
Remembers backup set location
Knows what need to backed up
Knows what is required for recovery
Knows what backups are redundant

475. UNDERSTANDING THE RMAN ARCHITECTURE
An oracle RMAN comprises of
RMAN EXECUTABLE This could be present and fired even through client side
TARGET DATABASE This is the database which needs to be backed up .
RECOVERY CATALOG Recovery catalog is optional otherwise backup details are stored in target database controlfile .
It is a repository of information queried and updated by Recovery Manager
It is a schema or user stored in Oracle database. One schema can support many databases
It contains information about physical schema of target database datafile and archive log ,backup sets and pieces Recovery catalog is a must in following scenarios
. In order to store scripts
. For tablespace point in time recovery

Media Management Software
Media Management software is a must if you are using RMAN for storing backup in tape drive directly.

Backups in RMAN
Oracle backups in RMAN are of the following type
RMAN complete backup OR RMAN incremental backup
These backups are of RMAN proprietary nature

IMAGE COPY
The advantage of uing Image copy is its not in RMAN proprietary format..

Backup Format
RMAN backup is not in oracle format but in RMAN format. Oracle backup comprises of backup sets and it consists of backup pieces. Backup sets are logical entity In oracle 9i it gets stored in a default location There are two type of backup sets Datafile backup sets, Archivelog backup sets One more important point of data file backup sets is it do not include empty blocks. A backup set would contain many backup pieces.
A single backup piece consists of physical files which are in RMAN proprietary format.

Example of taking backup using RMAN
Taking RMAN Backup
In non archive mode in dos prompt type
RMAN
You get the RMAN prompt
RMAN > Connect Target
Connect to target database : Magic
using target database controlfile instead of recovery catalog

Lets take a simple backup of database in non archive mode
shutdown immediate ; - - Shutdowns the database
startup mount
backup database ;- its start backing the database
alter database open;
We can fire the same command in archive log mode
And whole of datafiles will be backed
Backup database plus archivelog;

Restoring database
Restoring database has been made very simple in 9i .
It is just
Restore database..
RMAN has become intelligent to identify which datafiles has to be restored
and the location of backuped up file.

Oracle Enhancement for RMAN in 10 G

Flash Recovery Area
Right now the price of hard disk is falling. Many dba are taking oracle database backup inside the hard disk itself since it results in lesser mean time between recoverability.
The new parameter introduced is
DB_RECOVERY_FILE_DEST = /oracle/flash_recovery_area
By configuring the RMAN RETENTION POLICY the flash recovery area will automatically delete obsolete backups and archive logs that are no longer required based on that configuration Oracle has introduced new features in incremental backup

Change Tracking File
Oracle 10g has the facility to deliver faster incrementals with the implementation of changed tracking file feature.This will results in faster backups lesser space consumption and also reduces the time needed for daily backups

Incrementally Updated Backups
Oracle database 10g Incrementally Updates Backup features merges the image copy of a datafile with RMAN incremental backup. The resulting image copy is now updated with block changes captured by incremental backups.The merging of the image copy and incremental backup is initiated with RMAN recover command. This results in faster recovery.

Binary compression technique reduces backup space usage by 50-75%.

With the new DURATION option for the RMAN BACKUP command, DBAs can weigh backup performance against system service level requirements. By specifying a duration, RMAN will automatically calculate the appropriate backup rate; in addition, DBAs can optionally specify whether backups should minimize time or system load.

New Features in Oem to identify RMAN related backup like backup pieces, backup sets and image copy

Oracle 9i New features Persistent RMAN Configuration
A new configure command has been introduced in Oracle 9i , that lets you configure various features including automatic channels, parallelism ,backup options, etc.
These automatic allocations and options can be overridden by commands in a RMAN command file.

Controlfile Auto backups
Through this new feature RMAN will automatically perform a controlfile auto backup. after every backup or copy command.

Block Media Recovery
If we can restore a few blocks rather than an entire file we only need few blocks.
We even dont need to bring the data file offline.
Syntax for it as follows
Block Recover datafile 8 block 22;

Configure Backup Optimization
Prior to 9i whenever we backed up database using RMAN our backup also used take backup of read only table spaces which had already been backed up and also the same with archive log too.
Now with 9i backup optimization parameter we can prevent repeat backup of read only tablespace and archive log. The command for this is as follows Configure backup optimization on

Archive Log failover
If RMAN cannot read a block in an archived log from a destination. RMAN automatically attempts to read from an alternate location this is called as archive log failover

There are additional commands like
backup database not backed up since time '31-jan-2002 14:00:00'
Do not backup previously backed up files
(say a previous backup failed and you want to restart from where it left off).
Similar syntax is supported for restores
backup device sbt backup set all Copy a disk backup to tape
(backing up a backup
Additionally it supports
. Backup of server parameter file
. Parallel operation supported
. Extensive reporting available
. Scripting
. Duplex backup sets
. Corrupt block detection
. Backup archive logs

Pitfalls of using RMAN
Previous to version Oracle 9i backups were not that easy which means you had to allocate a channel compulsorily to take backup You had to give a run etc . The syntax was a bit complex …RMAN has now become very simple and easy to use..
If you changed the location of backup set it is compulsory for you to register it using RMAN or while you are trying to restore backup It resulted in hanging situations
There is no method to know whether during recovery database restore is going to fail because of missing archive log file.
Compulsory Media Management only if using tape backup
Incremental backups though used to consume less space used to be slower since it used to read the entire database to find the changed blocks and also They have difficult time streaming the tape device. .
Considerable improvement has been made in 10g to optimize the algorithm to handle changed block.

Observation
Introduced in Oracle 8 it has become more powerful and simpler with newer version of Oracle 9 and 10 g.
So if you really don't want to miss something critical please start using RMAN.

476. What is the use of break group? What are the various sub events a mouse double click event involves?
A break group is used to display one record for one group ones. While multiple related records in other group can be displayed.

477. What tuning indicators can one use? (for DBA)
The following high-level tuning indicators can be used to establish if a database is performing optimally or not:
. Buffer Cache Hit Ratio
Formula: Hit Ratio = (Logical Reads - Physical Reads) / Logical Reads
Action: Increase DB_CACHE_SIZE (DB_BLOCK_BUFFERS prior to 9i) to increase hit ratio
. Library Cache Hit Ratio
Action: Increase the SHARED_POOL_SIZE to increase hit ratio

478. What tools/utilities does Oracle provide to assist with performance tuning? (for DBA)
Oracle provide the following tools/ utilities to assist with performance monitoring and tuning:
. TKProf
. UTLBSTAT.SQL and UTLESTAT.SQL - Begin and end stats monitoring
. Statspack
. Oracle Enterprise Manager - Tuning Pack

479. What is STATSPACK and how does one use it? (for DBA)
Statspack is a set of performance monitoring and reporting utilities provided by Oracle from Oracle8i and above. Statspack provides improved BSTAT/ESTAT functionality, though the old BSTAT/ESTAT scripts are still available. For more information about STATSPACK, read the documentation in file $ORACLE_HOME/rdbms/admin/spdoc.txt.
Install Statspack:
cd $ORACLE_HOME/rdbms/admin
sqlplus "/ as sysdba" @spdrop.sql -- Install Statspack -
sqlplus "/ as sysdba" @spcreate.sql-- Enter tablespace names when prompted
Use Statspack:
sqlplus perfstat/perfstat
exec statspack.snap; -- Take a performance snapshots
exec statspack.snap;
o Get a list of snapshots
select SNAP_ID, SNAP_TIME from STATS$SNAPSHOT;
@spreport.sql -- Enter two snapshot id's for difference report
Other Statspack Scripts:
. sppurge.sql - Purge a range of Snapshot Id's between the specified begin and end Snap Id's
. spauto.sql - Schedule a dbms_job to automate the collection of STATPACK statistics
. spcreate.sql - Installs the STATSPACK user, tables and package on a database (Run as SYS).
. spdrop.sql - Deinstall STATSPACK from database (Run as SYS)
. sppurge.sql - Delete a range of Snapshot Id's from the database
. spreport.sql - Report on differences between values recorded in two snapshots
. sptrunc.sql - Truncates all data in Statspack tables

480. What are the common RMAN errors (with solutions)? (for DBA)
Some of the common RMAN errors are:
RMAN-20242: Specification does not match any archivelog in the recovery catalog.
Add to RMAN script: sql 'alter system archive log current';
RMAN-06089: archived log xyz not found or out of sync with catalog
Execute from RMAN: change archivelog all validate;

481. How can you execute the user defined triggers in forms 3.0 ?
Execute Trigger (trigger-name)

482. What ERASE package procedure does ?
Erase removes an indicated global variable.

483. What is the difference between NAME_IN and COPY ?
Copy is package procedure and writes values into a field.
Name in is a package function and returns the contents of the variable to which you apply.

484. What package procedure is used for calling another form ?
Call (E.g. Call(formname)

485. When the form is running in DEBUG mode, If you want to examine the values of global variables and other form variables, What package procedure command you would use in your trigger text ?
Break.
SYSTEM VARIABLES

486. The value recorded in system.last_record variable is of type
a. Number
b. Boolean
c. Character. ?
b. Boolean.

487. What is mean by Program Global Area (PGA) ?
It is area in memory that is used by a Single Oracle User Process.

488. What is hit ratio ?
It is a measure of well the data cache buffer is handling requests for data. Hit Ratio = (Logical Reads - Physical Reads - Hits Misses)/ Logical Reads.

489. How do u implement the If statement in the Select Statement
We can implement the if statement in the select statement by using the Decode statement. e.g. select DECODE (EMP_CAT,'1','First','2','Second'Null); Here the Null is the else statement where null is done .

490. How many types of Exceptions are there
There are 2 types of exceptions. They are
a) System Exceptions
e.g. When no_data_found, When too_many_rows
b) User Defined Exceptions
e.g. My_exception exception
When My_exception then

491. What are the inline and the precompiler directives
The inline and precompiler directives detect the values directly

492. How do you use the same lov for 2 columns
We can use the same lov for 2 columns by passing the return values in global values and using the global values in the code

493. How many minimum groups are required for a matrix report
The minimum number of groups in matrix report are 4

494. What is the difference between static and dynamic lov
The static lov contains the predetermined values while the dynamic lov contains values that come at run time

495. How does one manage Oracle database users? (for DBA)
Oracle user accounts can be locked, unlocked, forced to choose new passwords, etc. For example, all accounts except SYS and SYSTEM will be locked after creating an Oracle9iDB database using the DB Configuration Assistant (dbca). DBA's must unlock these accounts to make them available to users.
Look at these examples:
ALTER USER scott ACCOUNT LOCK -- lock a user account
ALTER USER scott ACCOUNT UNLOCK; -- unlocks a locked users account
ALTER USER scott PASSWORD EXPIRE; -- Force user to choose a new password

496. What is the difference between DBFile Sequential and Scattered Reads?(for DBA)
Both "db file sequential read" and "db file scattered read" events signify time waited for I/O read requests to complete. Time is reported in 100's of a second for Oracle 8i releases and below, and 1000's of a second for Oracle 9i and above. Most people confuse these events with each other as they think of how data is read from disk. Instead they should think of how data is read into the SGA buffer cache.
db file sequential read:
A sequential read operation reads data into contiguous memory (usually a single-block read with p3=1, but can be multiple blocks). Single block I/Os are usually the result of using indexes. This event is also used for rebuilding the control file and reading data file headers (P2=1). In general, this event is indicative of disk contention on index reads.
db file scattered read:
Similar to db file sequential reads, except that the session is reading multiple data blocks and scatters them into different discontinuous buffers in the SGA. This statistic is NORMALLY indicating disk contention on full table scans. Rarely, data from full table scans could be fitted into a contiguous buffer area, these waits would then show up as sequential reads instead of scattered reads.
The following query shows average wait time for sequential versus scattered reads:
prompt "AVERAGE WAIT TIME FOR READ REQUESTS"
select a.average_wait "SEQ READ", b.average_wait "SCAT READ"
from sys.v_$system_event a, sys.v_$system_event b
where a.event = 'db file sequential read'
and b.event = 'db file scattered read';

497. What is the use of PARFILE option in EXP command ?
Name of the parameter file to be passed for export.

498. What is the use of TABLES option in EXP command ?
List of tables should be exported.ze)

499. What is the OPTIMAL parameter?
It is used to set the optimal length of a rollback segment.

500. How does one use ORADEBUG from Server Manager/ SQL*Plus? (for DBA)
Execute the "ORADEBUG HELP" command from svrmgrl or sqlplus to obtain a list of valid ORADEBUG commands. Look at these examples:
SQLPLUS> REM Trace SQL statements with bind variables
SQLPLUS> oradebug setospid 10121
Oracle pid: 91, Unix process pid: 10121, image: oracleorcl
SQLPLUS> oradebug EVENT 10046 trace name context forever, level 12
Statement processed.
SQLPLUS> ! vi /app/oracle/admin/orcl/bdump/ora_10121.trc
SQLPLUS> REM Trace Process Statistics
SQLPLUS> oradebug setorapid 2
Unix process pid: 1436, image: ora_pmon_orcl
SQLPLUS> oradebug procstat
Statement processed.
SQLPLUS>> oradebug TRACEFILE_NAME
/app/oracle/admin/orcl/bdump/pmon_1436.trc
SQLPLUS> REM List semaphores and shared memory segments in use
SQLPLUS> oradebug ipc
SQLPLUS> REM Dump Error Stack
SQLPLUS> oradebug setospid <pid>
SQLPLUS> oradebug event immediate trace name errorstack level 3
SQLPLUS> REM Dump Parallel Server DLM locks
SQLPLUS> oradebug lkdebug -a convlock
SQLPLUS> oradebug lkdebug -a convres
SQLPLUS> oradebug lkdebug -r <resource handle> (i.e 0x8066d338 from convres dump)

501. Are there any undocumented commands in Oracle? (for DBA)
Sure there are, but it is hard to find them. Look at these examples:
From Server Manager (Oracle7.3 and above): ORADEBUG HELP
It looks like one can change memory locations with the ORADEBUG POKE command. Anyone brave enough to test this one for us? Previously this functionality was available with ORADBX (ls -l $ORACLE_HOME/rdbms/lib/oradbx.o; make -f oracle.mk oradbx) SQL*Plus: ALTER SESSION SET CURRENT_SCHEMA = SYS

502. What is the function of Optimizer ?
The goal of the optimizer is to choose the most efficient way to execute a SQL statement.

503. What is Execution Plan ?
The combinations of the steps the optimizer chooses to execute a statement is called an execution plan.

504. Can one resize tablespaces and data files? (for DBA)
One can manually increase or decrease the size of a datafile from Oracle 7.2 using the command.
ALTER DATABASE DATAFILE 'filename2' RESIZE 100M;
Because you can change the sizes of datafiles, you can add more space to your database without adding more datafiles. This is beneficial if you are concerned about reaching the maximum number of datafiles allowed in your database.
Manually reducing the sizes of datafiles allows you to reclaim unused space in the database. This is useful for correcting errors in estimations of space requirements.
Also, datafiles can be allowed to automatically extend if more space is required. Look at the following command:
CREATE TABLESPACE pcs_data_ts
DATAFILE 'c:\ora_apps\pcs\pcsdata1.dbf' SIZE 3M
AUTOEXTEND ON NEXT 1M MAXSIZE UNLIMITED
DEFAULT STORAGE (INITIAL 10240
NEXT 10240
MINEXTENTS 1
MAXEXTENTS UNLIMITED
PCTINCREASE 0)
ONLINE
PERMANENT;

505. What is SAVE POINT ?
For long transactions that contain many SQL statements, intermediate markers or savepoints can be declared which can be used to divide a transaction into smaller parts. This allows the option of later rolling back all work performed from the current point in the transaction to a declared savepoint within the transaction.

506. What are the values that can be specified for OPTIMIZER MODE Parameter ?
COST and RULE.

507. Can one rename a tablespace? (for DBA)
No, this is listed as Enhancement Request 148742. Workaround:
Export all of the objects from the tablespace
Drop the tablespace including contents
Recreate the tablespace
Import the objects

508. What is RULE-based approach to optimization ?
Choosing an executing planbased on the access paths available and the ranks of these access paths.

509. What are the values that can be specified for OPTIMIZER_GOAL parameter of the ALTER SESSION Command ?
CHOOSE,ALL_ROWS,FIRST_ROWS and RULE.

510. How does one create a standby database? (for DBA)
While your production database is running, take an (image copy) backup and restore it on duplicate hardware. Note that an export will not work!!!
On your standby database, issue the following commands:
ALTER DATABASE CREATE STANDBY CONTROLFILE AS 'filename';
ALTER DATABASE MOUNT STANDBY DATABASE;
RECOVER STANDBY DATABASE;
On systems prior to Oracle 8i, write a job to copy archived redo log files from the primary database to the standby system, and apply the redo log files to the standby database (pipe it). Remember the database is recovering and will prompt you for the next log file to apply.
Oracle 8i onwards provide an "Automated Standby Database" feature, which will send archived, log files to the remote site via NET8, and apply then to the standby database.
When one needs to activate the standby database, stop the recovery process and activate it:
ALTER DATABASE ACTIVATE STANDBY DATABASE;

511. How does one give developers access to trace files (required as input to tkprof)? (for DBA)
The "alter session set sql_trace=true" command generates trace files in USER_DUMP_DEST that can be used by developers as input to tkprof. On Unix the default file mask for these files are "rwx r-- ---".
There is an undocumented INIT.ORA parameter that will allow everyone to read (rwx r-r--) these trace files:
_trace_files_public = true
Include this in your INIT.ORA file and bounce your database for it to take effect.

512. What are the responsibilities of a Database Administrator ?
Installing and upgrading the Oracle Server and application tools. Allocating system storage and planning future storage requirements for the database system. Managing primary database structures (tablespaces) Managing primary objects (table,views,indexes) Enrolling users and maintaining system security. Ensuring compliance with Oralce license agreement Controlling and monitoring user access to the database. Monitoring and optimizing the performance of the database. Planning for backup and recovery of database information. Maintain archived data on tape Backing up and restoring the database. Contacting Oracle Corporation for technical support.

513. What is a trace file and how is it created ?
Each server and background process can write an associated trace file. When an internal error is detected by a process or user process, it dumps information about the error to its trace. This can be used for tuning the database.

514. What are the roles and user accounts created automatically with the database?
DBA - role Contains all database system privileges.
SYS user account - The DBA role will be assigned to this account. All of the base tables and views for the database's dictionary are store in this schema and are manipulated only by ORACLE. SYSTEM user account - It has all the system privileges for the database and additional tables and views that display administrative information and internal tables and views used by oracle tools are created using this username.

515. What are the minimum parameters should exist in the parameter file (init.ora) ?
DB NAME - Must set to a text string of no more than 8 characters and it will be stored inside the datafiles, redo log files and control files and control file while database creation.
DB_DOMAIN - It is string that specifies the network domain where the database is created. The global database name is identified by setting these parameters
(DB_NAME & DB_DOMAIN) CONTORL FILES - List of control filenames of the database. If name is not mentioned then default name will be used.
DB_BLOCK_BUFFERS - To determine the no of buffers in the buffer cache in SGA.
PROCESSES - To determine number of operating system processes that can be connected to ORACLE concurrently. The value should be 5 (background process) and additional 1 for each user.
ROLLBACK_SEGMENTS - List of rollback segments an ORACLE instance acquires at database startup. Also optionally LICENSE_MAX_SESSIONS,LICENSE_SESSION_WARNING and LICENSE_MAX_USERS.

516. Why and when should I backup my database? (for DBA)
Backup and recovery is one of the most important aspects of a DBAs job. If you lose your company's data, you could very well lose your job. Hardware and software can always be replaced, but your data may be irreplaceable!
Normally one would schedule a hierarchy of daily, weekly and monthly backups, however consult with your users before deciding on a backup schedule. Backup frequency normally depends on the following factors:
. Rate of data change/ transaction rate
. Database availability/ Can you shutdown for cold backups?
. Criticality of the data/ Value of the data to the company
. Read-only tablespace needs backing up just once right after you make it read-only
. If you are running in archivelog mode you can backup parts of a database over an extended cycle of days
. If archive logging is enabled one needs to backup archived log files timeously to prevent database freezes
. Etc.
Carefully plan backup retention periods. Ensure enough backup media (tapes) are available and that old backups are expired in-time to make media available for new backups. Off-site vaulting is also highly recommended.
Frequently test your ability to recover and document all possible scenarios. Remember, it's the little things that will get you. Most failed recoveries are a result of organizational errors and miscommunications.

517. What strategies are available for backing-up an Oracle database? (for DBA)
The following methods are valid for backing-up an Oracle database:
Export/Import - Exports are "logical" database backups in that they extract logical definitions and data from the database to a file.
Cold or Off-line Backups - Shut the database down and backup up ALL data, log, and control files.
Hot or On-line Backups - If the databases are available and in ARCHIVELOG mode, set the tablespaces into backup mode and backup their files. Also remember to backup the control files and archived redo log files.
RMAN Backups - While the database is off-line or on-line, use the "rman" utility to backup the database.
It is advisable to use more than one of these methods to backup your database. For example, if you choose to do on-line database backups, also cover yourself by doing database exports. Also test ALL backup and recovery scenarios carefully. It is better to be save than sorry.
Regardless of your strategy, also remember to backup all required software libraries, parameter files, password files, etc. If your database is in ARCGIVELOG mode, you also need to backup archived log files.

518. What is the difference between online and offline backups? (for DBA)
A hot backup is a backup performed while the database is online and available for read/write. Except for Oracle exports, one can only do on-line backups when running in ARCHIVELOG mode.
A cold backup is a backup performed while the database is off-line and unavailable to its users.

519. What is the difference between restoring and recovering? (for DBA)
Restoring involves copying backup files from secondary storage (backup media) to disk. This can be done to replace damaged files or to copy/move a database to a new location.
Recovery is the process of applying redo logs to the database to roll it forward. One can roll-forward until a specific point-in-time (before the disaster occurred), or roll-forward until the last transaction recorded in the log files. Sql> connect SYS as SYSDBA
Sql> RECOVER DATABASE UNTIL TIME '2001-03-06:16:00:00' USING BACKUP CONTROLFILE;

520. How does one backup a database using the export utility? (for DBA)
Oracle exports are "logical" database backups (not physical) as they extract data and logical definitions from the database into a file. Other backup strategies normally back-up the physical data files.
One of the advantages of exports is that one can selectively re-import tables, however one cannot roll-forward from an restored export file. To completely restore a database from an export file one practically needs to recreate the entire database.
Always do full system level exports (FULL=YES). Full exports include more information about the database in the export file than user level exports.

521. What are the built_ins used the display the LOV?
Show_lov
List_values

522. How do you call other Oracle Products from Oracle Forms?
Run_product is a built-in, Used to invoke one of the supported oracle tools products and specifies the name of the document or module to be run. If the called product is unavailable at the time of the call, Oracle Forms returns a message to the operator.

523. What is the main diff. bet. Reports 2.0 & Reports 2.5?
Report 2.5 is object oriented.

524. What are the Built-ins to display the user-named editor?
A user named editor can be displayed programmatically with the built in procedure SHOW-EDITOR, EDIT_TETITEM independent of any particular text item.

525. How many number of columns a record group can have?
A record group can have an unlimited number of columns of type CHAR, LONG, NUMBER, or DATE provided that the total number of column does not exceed 64K.

526. What is a Query Record Group?
A query record group is a record group that has an associated SELECT statement. The columns in a query record group derive their default names, data types, had lengths from the database columns referenced in the SELECT statement. The records in query record group are the rows retrieved by the query associated with that record group.

527. What does the term panel refer to with regard to pages?
A panel is the no. of physical pages needed to print one logical page.

528. What is a master detail relationship?
A master detail relationship is an association between two base table blocks- a master block and a detail block. The relationship between the blocks reflects a primary key to foreign key relationship between the tables on which the blocks are based.

529. What is a library?
A library is a collection of subprograms including user named procedures, functions and packages.

530. What is an anchoring object & what is its use? What are the various sub events a mouse double click event involves?
An anchoring object is a print condition object which used to explicitly or implicitly anchor other objects to itself.

531. Use the add_group_column function to add a column to record group that was created at a design time?
False

532. What are the various sub events a mouse double click event involves? What are the various sub events a mouse double click event involves?
Double clicking the mouse consists of the mouse down, mouse up, mouse click, mouse down & mouse up events.

533. What command would you use to create a backup control file?
Alter database backup control file to trace.

534. Give the stages of instance startup to a usable state where normal users may access it.
STARTUP NOMOUNT - Instance startup
STARTUP MOUNT - The database is mounted
STARTUP OPEN - The database is opened

535. What column differentiates the V$ views to the GV$ views and how?
The INST_ID column which indicates the instance in a RAC environment the information came from.

536. How would you go about generating an EXPLAIN plan?
Create a plan table with utlxplan.sql.
Use the explain plan set statement_id = 'tst1' into plan_table for a SQL statement
Look at the explain plan with utlxplp.sql or utlxpls.sql

537. How would you go about increasing the buffer cache hit ratio?
Use the buffer cache advisory over a given workload and then query the v$db_cache_advice table. If a change was necessary then I would use the alter system set db_cache_size command.

538. Explain an ORA-01555
You get this error when you get a snapshot too old within rollback. It can usually be solved by increasing the undo retention or increasing the size of rollbacks. You should also look at the logic involved in the application getting the error message.

539. Explain the difference between $ORACLE_HOME and $ORACLE_BASE.
ORACLE_BASE is the root directory for oracle. ORACLE_HOME located beneath ORACLE_BASE is where the oracle products reside.

540. How would you determine the time zone under which a database was operating?
select DBTIMEZONE from dual;

541. Explain the use of setting GLOBAL_NAMES equal to TRUE.
Setting GLOBAL_NAMES dictates how you might connect to a database. This variable is either TRUE or FALSE and if it is set to TRUE it enforces database links to have the same name as the remote database to which they are linking.

542. What command would you use to encrypt a PL/SQL application?
WRAP

543. Explain the difference between a FUNCTION, PROCEDURE and PACKAGE.
A function and procedure are the same in that they are intended to be a collection of PL/SQL code that carries a single task. While a procedure does not have to return any values to the calling application, a function will return a single value. A package on the other hand is a collection of functions and procedures that are grouped together based on their commonality to a business function or application.

544. Explain the use of table functions.
Table functions are designed to return a set of rows through PL/SQL logic but are intended to be used as a normal table or view in a SQL statement. They are also used to pipeline information in an ETL process.

545. Name three advisory statistics you can collect.
Buffer Cache Advice, Segment Level Statistics, & Timed Statistics

546. Where in the Oracle directory tree structure are audit traces placed?
In unix $ORACLE_HOME/rdbms/audit, in Windows the event viewer

547. Explain materialized views and how they are used.
Materialized views are objects that are reduced sets of information that have been summarized, grouped, or aggregated from base tables. They are typically used in data warehouse or decision support systems.

548. When a user process fails, what background process cleans up after it?
PMON

549. What background process refreshes materialized views?
The Job Queue Processes.

550. How would you determine what sessions are connected and what resources they are waiting for?
Use of V$SESSION and V$SESSION_WAIT

551. Describe what redo logs are.
Redo logs are logical and physical structures that are designed to hold all the changes made to a database and are intended to aid in the recovery of a database.

552. How would you force a log switch?
ALTER SYSTEM SWITCH LOGFILE;

553. Give two methods you could use to determine what DDL changes have been made.
You could use Logminer or Streams

554. What does coalescing a tablespace do?
Coalescing is only valid for dictionary-managed tablespaces and de-fragments space by combining neighboring free extents into large single extents.

555. What is the difference between a TEMPORARY tablespace and a PERMANENT tablespace?
A temporary tablespace is used for temporary objects such as sort structures while permanent tablespaces are used to store those objects meant to be used as the true objects of the database.

556. Name a tablespace automatically created when you create a database.
The SYSTEM tablespace.

557. When creating a user, what permissions must you grant to allow them to connect to the database?
Grant the CONNECT to the user.

558. How do you add a data file to a tablespace
ALTER TABLESPACE <tablespace_name> ADD DATAFILE <datafile_name> SIZE

559. How do you resize a data file?
ALTER DATABASE DATAFILE <datafile_name> RESIZE <new_size>;

560. What view would you use to look at the size of a data file?
DBA_DATA_FILES

561. What view would you use to determine free space in a tablespace?
DBA_FREE_SPACE

562. How would you determine who has added a row to a table?
Turn on fine grain auditing for the table.

563. How can you rebuild an index?
ALTER INDEX <index_name> REBUILD;

564. Explain what partitioning is and what its benefit is.
Partitioning is a method of taking large tables and indexes and splitting them into smaller, more manageable pieces.

565. You have just compiled a PL/SQL package but got errors, how would you view the errors?
SHOW ERRORS

566. How can you gather statistics on a table?
The ANALYZE command.

567. How can you enable a trace for a session?
Use the DBMS_SESSION.SET_SQL_TRACE or
Use ALTER SESSION SET SQL_TRACE = TRUE;

568. What is the difference between the SQL*Loader and IMPORT utilities?
These two Oracle utilities are used for loading data into the database. The difference is that the import utility relies on the data being produced by another Oracle utility EXPORT while the SQL*Loader utility allows data to be loaded that has been produced by other utilities from different data sources just so long as it conforms to ASCII formatted or delimited files.

569. Name two files used for network connection to a database.
TNSNAMES.ORA and SQLNET.ORA

570. How do you trap the error in forms 3.0 ?
using On-Message or On-Error triggers.

571. How many pages you can in a single form ?
Unlimited

572. While specifying master/detail relationship between two blocks specifying the join condition is a must ?
True or False. ?
True

573. EXIT_FORM is a restricted package procedure ?
a. True b. False
True

574. What is the usage of an ON-INSERT,ON-DELETE and ON-UPDATE TRIGGERS ?
These triggers are executes when inserting, deleting and updating operations are performed and can be used to change the default function of insert, delete or update respectively. For Eg, instead of inserting a row in a table an existing row can be updated in the same table.

575. What are the types of Pop-up window ?
the pop-up field editor
pop-up list of values
pop-up pages.
Alert :

576. What is an SQL *FORMS ?
SQL *forms is 4GL tool for developing and executing; Oracle based interactive application.

577. How do you control the constraints in forms ?
Select the use constraint property is ON Block definition screen.
BLOCK

578. What is the difference between restricted and unrestricted package procedure ?
Restricted package procedure that affects the basic functions of SQL * Forms. It cannot used in all triggers except key triggers. Unrestricted package procedure that does not interfere with the basic functions of SQL * Forms it can be used in any triggers.

579. A query fetched 10 records How many times does a PRE-QUERY Trigger and POST-QUERY Trigger will get executed ?
PRE-QUERY fires once.
POST-QUERY fires 10 times.

580. Give the sequence in which triggers fired during insert operations, when the following 3 triggers are defined at the same block level ?
a. ON-INSERT b. POST-INSERT c. PRE-INSERT

581. State the order in which these triggers are executed ?
POST-FIELD,ON-VALIDATE-FIELD,POST-CHANGE and KEY-NEXTFLD. KEY-NEXTFLD,POST-CHANGE, ON-VALIDATE-FIELD, POST-FIELD. g.

582. What the PAUSE package procedure does ?
Pause suspends processing until the operator presses a function key

583. What do you mean by a page ?
Pages are collection of display information, such as constant text and graphics

584. What are the type of User Exits ?
ORACLE Precompliers user exits
OCI (ORACLE Call Interface)
Non-ORACEL user exits.
Page :

585. What is the difference between an ON-VALIDATE-FIELD trigger and a trigger ?
On-validate-field trigger fires, when the field Validation status New or changed. Post-field-trigger whenever the control leaving form the field, it will fire.

586. Can we use a restricted package procedure in ON-VALIDATE-FIELD Trigger ?
No

587. Is a Key startup trigger fires as result of a operator pressing a key explicitly ?
No

588. Can we use GO-BLOCK package in a pre-field trigger ?
No

589. Can we create two blocks with the same name in form 3.0 ?
No

590. What does an on-clear-block Trigger fire?
It fires just before SQL * forms the current block.

591. Name the two files that are created when you generate the form give the filex extension ?
INP (Source File)
FRM (Executable File)

592. What package procedure used for invoke sql *plus from sql *forms ?
Host (E.g. Host (sqlplus))

593. What is the significance of PAGE 0 in forms 3.0 ?
Hide the fields for internal calculation.

594. What are the different types of key triggers ?
Function Key
Key-function
Key-others
Key-startup

595. What is the difference between a Function Key Trigger and Key Function Trigger ?
Function key triggers are associated with individual SQL*FORMS function keys You can attach Key function triggers to 10 keys or key sequences that normally do not perform any SQL * FORMS operations. These keys referred as key F0 through key F9.

596. Committed block sometimes refer to a BASE TABLE ?
False

597. Error_Code is a package proecdure ?
a. True b. false
False

598. What are the unrestricted procedures used to change the popup screen position during run time ?
Anchor-view
Resize -View
Move-View.

599. What is an Alert ?
An alert is window that appears in the middle of the screen overlaying a portion of the current display.

600. Deleting a page removes information about all the fields in that page ?
a. True. b. False
a. True.

601. Two popup pages can appear on the screen at a time ?Two popup pages can appear on the screen at a time ?
a. True. b. False?
a. True.

602. Classify the restricted and unrestricted procedure from the following.
a. Call
b. User-Exit
c. Call-Query
d. Up
e. Execute-Query
f. Message
g. Exit-From
h. Post
i. Break?

a. Call - unrestricted
b. User Exit - Unrestricted
c. Call_query - Unrestricted
d. Up - Restricted
e. Execute Query - Restricted
f. Message - Restricted
g. Exit_form - Restricted
h. Post - Restricted
i. Break - Unrestricted.

603. What is an User Exits ?
A user exit is a subroutine which are written in programming languages using pro*C pro *Cobol , etc., that link into the SQL * forms executable.

604. What is a Trigger ?
A piece of logic that is executed at or triggered by a SQL *forms event.

605. What is a Package Procedure ?
A Package procedure is built in PL/SQL procedure.

606. What is the maximum size of a form ?
255 character width and 255 characters Length.

607. What is the difference between system.current_field and system.cursor_field ?
1. System.current_field gives name of the field.
2. System.cursor_field gives name of the field with block name.

608. List the system variables related in Block and Field?
1. System.block_status
2. System.current_block
3. System.current_field
4. System.current_value
5. System.cursor_block
6. System.cursor_field
7. System.field_status.

609. What are the different types of Package Procedure ?
1. Restricted package procedure.
2. Unrestricted package procedure.

610. What are the types of TRIGGERS ?
1. Navigational Triggers.
2. Transaction Triggers.

611. Identify package function from the following ?
1. Error-Code
2. Break
3. Call
4. Error-text
5. Form-failure
6. Form-fatal
7. Execute-query
8. Anchor View
9. Message_code?

1. Error_Code
2. Error_Text
3. Form_Failure
4. Form_Fatal
5. Message_Code

612. Can you attach an lov to a field at run-time? if yes, give the build-in name.?
Yes. Set_item_proprety

613. Is it possible to attach same library to more than one form?
Yes

614. Can you attach an lov to a field at design time?
Yes

615. List the windows event triggers available in Forms 4.0?
When-window-activated,
when-window-closed,
when-window-deactivated,
when-window-resized

616. What are the triggers associated with the image item?
When-Image-activated(Fires when the operator double clicks on an image Items)
When-image-pressed(fires when the operator selects or deselects the image item)

617. What is a visual attribute?
Visual Attributes are the font, color and pattern characteristics of objects that operators see and intract with in our application.

618. How many maximum number of radio buttons can you assign to a radio group?
Unlimited no of radio buttons can be assigned to a radio group

619. What are the different types of segments?
Data segment, index segment, rollback segment and temporary segment.

620. What is a data segment?
Each non-clustered table has a data segment. All of the table's data is stored in the extents of its data segment. Each cluster has a data segment. The data of every table in the cluster is stored in the cluster's data segment.

621. What is an index segment?
Each index has an index segment that stores all of its data.

622. What is rollback segment?
A database contains one or more rollback segments to temporarily store "undo" information.

623. What are the uses of rollback segment?
To generate read-consistent database information during database recovery and to rollback uncommitted transactions by the users.

624. What is a temporary segment?
Temporary segments are created by Oracle when a SQL statement needs a temporary work area to complete execution. When the statement finishes execution, the temporary segment extents are released to the system for future use.

625. What is a datafile?
Every Oracle database has one or more physical data files. A database's data files contain all the database data. The data of logical database structures such as tables and indexes is physically stored in the data files allocated for a database.

626. What are the characteristics of data files?
A data file can be associated with only one database. Once created a data file can't change size. One or more data files form a logical unit of database storage called a tablespace.

627. What is a redo log?
The set of redo log files for a database is collectively known as the database redo log.

628. What is the function of redo log?
The primary function of the redo log is to record all changes made to data.

629. What is the use of redo log information?
The information in a redo log file is used only to recover the database from a system or media failure prevents database data from being written to a database's data files.

630. What does a control file contains?
- Database name
- Names and locations of a database's files and redolog files.
- Time stamp of database creation.

631. What is the use of control file?
When an instance of an Oracle database is started, its control file is used to identify the database and redo log files that must be opened for database operation to proceed. It is also used in database recovery.

632. Is it possible to split the print reviewer into more than one region?
Yes

633. Is it possible to center an object horizontally in a repeating frame that has a variable horizontal size?
Yes

634. For a field in a repeating frame, can the source come from the column which does not exist in the data group which forms the base for the frame?
Yes

635. Can a field be used in a report without it appearing in any data group?
Yes

636. The join defined by the default data link is an outer join yes or no?
Yes

637. Can a formula column referred to columns in higher group?
Yes

638. Can a formula column be obtained through a select statement?
Yes

639. Is it possible to insert comments into sql statements return in the data model editor?
Yes

640. Is it possible to disable the parameter from while running the report?
Yes

641. When a form is invoked with call_form, Does oracle forms issues a save point?
Yes

642. Explain the difference between a hot backup and a cold backup and the benefits associated with each.
A hot backup is basically taking a backup of the database while it is still up and running and it must be in archive log mode. A cold backup is taking a backup of the database while it is shut down and does not require being in archive log mode. The benefit of taking a hot backup is that the database is still available for use while the backup is occurring and you can recover the database to any point in time. The benefit of taking a cold backup is that it is typically easier to administer the backup and recovery process. In addition, since you are taking cold backups the database does not require being in archive log mode and thus there will be a slight performance gain as the database is not cutting archive logs to disk.

643. You have just had to restore from backup and do not have any control files. How would you go about bringing up this database?
I would create a text based backup control file, stipulating where on disk all the data files where and then issue the recover command with the using backup control file clause.

644. How do you switch from an init.ora file to a spfile?
Issue the create spfile from pfile command.

645. Explain the difference between a data block, an extent and a segment.
A data block is the smallest unit of logical storage for a database object. As objects grow they take chunks of additional storage that are composed of contiguous data blocks. These groupings of contiguous data blocks are called extents. All the extents that an object takes when grouped together are considered the segment of the database object.

646. Give two examples of how you might determine the structure of the table DEPT.
Use the describe command or use the dbms_metadata.get_ddl package.

647. Where would you look for errors from the database engine?
In the alert log.

648. Compare and contrast TRUNCATE and DELETE for a table.
Both the truncate and delete command have the desired outcome of getting rid of all the rows in a table. The difference between the two is that the truncate command is a DDL operation and just moves the high water mark and produces a now rollback. The delete command, on the other hand, is a DML operation, which will produce a rollback and thus take longer to complete.

649. Give the reasoning behind using an index.
Faster access to data blocks in a table.

650. Give the two types of tables involved in producing a star schema and the type of data they hold.
Fact tables and dimension tables. A fact table contains measurements while dimension tables will contain data that will help describe the fact tables.

651. What type of index should you use on a fact table?
A Bitmap index.

652. Give two examples of referential integrity constraints.
A primary key and a foreign key.

653. A table is classified as a parent table and you want to drop and re-create it. How would you do this without affecting the children tables?
Disable the foreign key constraint to the parent, drop the table, re-create the table, enable the foreign key constraint.

654. Explain the difference between ARCHIVELOG mode and NOARCHIVELOG mode and the benefits and disadvantages to each.
ARCHIVELOG mode is a mode that you can put the database in for creating a backup of all transactions that have occurred in the database so that you can recover to any point in time. NOARCHIVELOG mode is basically the absence of ARCHIVELOG mode and has the disadvantage of not being able to recover to any point in time. NOARCHIVELOG mode does have the advantage of not having to write transactions to an archive log and thus increases the performance of the database slightly.

655. What is an Lov?
A list of values is a single or multi column selection list displayed in a pop-up window

656. What is a record Group?
A record group is an internal oracle forms data structure that has a similar column/row frame work to a database table

657. Give built-in routine related to a record groups?
Create_group (Function)
Create_group_from_query(Function)
Delete_group(Procedure)
Add_group_column(Function)
Add_group_row(Procedure)
Delete_group_row(Procedure)
Populate_group(Function)
Populate_group_with_query(Function)
Set_group_Char_cell(procedure)

658. List the built-in routines for the controlling canvas views during run-time?
Find_canvas
Get-Canvas_property
Get_view_property
Hide_View
Replace_content_view
Scroll_view
Set_canvas_property
Set_view_property
Show_view
Alert

659. System.effective_date system variable is read only True/False?
False

660. What are the built_in used to trapping errors in forms 4?
Error_type return character
Error_code return number
Error_text return char
Dbms_error_code return no.
Dbms_error_text return char

661. What is Oracle Financials? (for DBA)
Oracle Financials products provide organizations with solutions to a wide range of long- and short-term accounting system issues. Regardless of the size of the business, Oracle Financials can meet accounting management demands with:
Oracle Assets: Ensures that an organization's property and equipment investment is accurate and that the correct asset tax accounting strategies are chosen.
Oracle General Ledger: Offers a complete solution to journal entry, budgeting, allocations, consolidation, and financial reporting needs.
Oracle Inventory: Helps an organization make better inventory decisions by minimizing stock and maximizing cash flow.
Oracle Order Entry: Provides organizations with a sophisticated order entry system for managing customer commitments.
Oracle Payables: Lets an organization process more invoices with fewer staff members and tighter controls. Helps save money through maximum discounts, bank float, and prevention of duplicate payment.
Oracle Personnel: Improves the management of employee- related issues by retaining and making available every form of personnel data.
Oracle Purchasing: Improves buying power, helps negotiate bigger discounts, eliminates paper flow, increases financial controls, and increases productivity.
Oracle Receivables:. Improves cash flow by letting an organization process more payments faster, without off-line research. Helps correctly account for cash, reduce outstanding receivables, and improve collection effectiveness.
Oracle Revenue Accounting Gives an organization timely and accurate revenue and flexible commissions reporting.
Oracle Sales Analysis: Allows for better forecasting, planning. and reporting of sales information.

662. What are the design facilities available in forms 4.0?
Default Block facility.
Layout Editor.
Menu Editor.
Object Lists.
Property Sheets.
PL/SQL Editor.
Tables Columns Browser.
Built-ins Browser.

663. What is the most important module in Oracle Financials? (for DBA)
The General Ledger (GL) module is the basis for all other Oracle Financial modules. All other modules provide information to it. If you implement Oracle Financials, you should switch your current GL system first.GL is relatively easy to implement. You should go live with it first to give your implementation team a chance to be familiar with Oracle Financials.

664. What are the types of canvas-views?
Content View, Stacked View.

665. What is the MultiOrg and what is it used for? (for DBA)
MultiOrg or Multiple Organizations Architecture allows multiple operating units and their relationships to be defined within a single installation of Oracle Applications. This keeps each operating unit's transaction data separate and secure.
Use the following query to determine if MuliOrg is intalled:
select multi_org_flag from fnd_product_groups;

666. What is the difference between Fields and FlexFields? (for DBA)
A field is a position on a form that one uses to enter, view, update, or delete information. A field prompt describes each field by telling what kind of information appears in the field, or alternatively, what kind of information should be entered in the field.
A flexfield is an Oracle Applications field made up of segments. Each segment has an assigned name and a set of valid values. Oracle Applications uses flexfields to capture information about your organization. There are two types of flexfields: key flexfields and descriptive flexfields.

667. Explain types of Block in forms4.0?
Base table Blocks.
Control Blocks.
1. A base table block is one that is associated with a specific database table or view.
2. A control block is a block that is not associated with a database table. ITEMS

668. What is an Alert?
An alert is a modal window that displays a message notifies the operator of some application condition

669. What are the built-in routines is available in forms 4.0 to create and manipulate a parameter list?
Add_parameter
Create_Parameter_list
Delete_parameter
Destroy_parameter_list
Get_parameter_attr
Get_parameter_list
set_parameter_attr

670. What is a record Group?
A record group is an internal oracle forms data structure that has a similar column/row frame work to a database table

671. What is a Navigable item?
A navigable item is one that operators can navigate to with the keyboard during default navigation, or that Oracle forms can navigate to by executing a navigational built-in procedure.

672. What is a library in Forms 4.0?
A library is a collection of Pl/SQL program units, including user named procedures, functions & packages

673. How image_items can be populate to field in forms 4.0?
A fetch from a long raw database column PL/Sql assignment to executing the read_image_file built_in procedure to get an image from the file system.

674. What is the content view and stacked view?
A content view is the "Base" view that occupies the entire content pane of the window in which it is displayed. A stacked view differs from a content canvas view in that it is not the base view for the window to which it is assigned

Koteswar Oracle Apps Techno Functional Blog

Thursday 10 May 2012

Oracle Interview Questions and Answers

Oracle Interview Questions and Answers

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